DMS_banner12.jpg (71459 bytes)
Home About Us Field Trips March Show Board/Officers Geogram Sample Meetings Members Links

 

 

 

 

 

                           Mineral of the Month--September 2007

                              Delaware Almandite Garnet

                                                   Iron Aluminum Silicate

                                        Fe3Al2(SiO4)3

 



                                        "Delaware Almandite Garnet"

                                              By Ken Casey

Preface
Introduction
Why Delaware Garnet?
What's in a name?
Chemistry & Science
Some Delaware Garnet Geology
Microscopic Garnet
Macroscopic Garnet
Other Garnet Experiences
Two Museums of Note
Uses
Links
Members' Gallery:
   Arthur Koch
Article Contributors
Photo & Graphics Credits
Suggested Reading
Invitation to Members
Past Minerals of the Month

deflag.gif (4102 bytes)
        Delaware State Flag

Image courtesy of Marchex, Inc.
2007, World Flag Database

 

Garnets abound in Delaware...

 

...to aid us in our geological knowledge quest!

(Top, left): Delaware Almandite Garnet, Wilmington, Delaware
Photo by Ken Casey 2004

(Top, right): Dodecahedral Garnet crystal, Roxbury, Connecticut
Photo by Ken Casey 2007

Preface    

    

     Greetings, my mineralogical friends!  This month, our Mineral-of-the-Month takes us
to protected parkland in New Castle County for any easy downhill hike.  Since we've been
inactive over the summer, this short jaunt will give our muscles a chance to acclimate to
hiking and climbing, once again. 

     We've got a busy schedule. The weather promises to be bright and sunny today, so Let's go!

 

Introduction

     

     Many states boast garnet as a draw for rockhounds.  Delaware is no different, except for
the facility to collect them. Most Delaware garnet occurs in public streams, partially-eroded
from it’s host rock over time.

     We can, however, take our pick of geology hikes to view them in situ. Or, as the Delaware
Geological Survey has organized itineraries for us, called GeoAdventures.  We''ll share a bit
from the Survey's suggestions, coupled with our club's and this author's field experience.

     Our article will touch upon some of the mineral assemblages in our state, which contain
garnet. In addition, we will take a virtual tour of one area, north of Wilmington, which exhibits
the most prolific of Delaware’s garnet landscapes.  Enjoy!

 

Why Delaware Garnet?

 

      Our local red garnet is both easy to locate and identify in the field, so it makes a perfect
choice to open a new season of fieldtrips.  As many states brag (and deservedly so) upon their
own garnet reserves, I believe that disseminating Delaware's contribution to the "garnet club" is
worthy of pursuing here.  And, we get to breathe the fresh country air of the Diamond State, while
seeking out our own garnet glory.  Please do join us!

 

     And, with a simple trail off of the entrance to the parks, such as to our Brandywine Creek State Park, north of Wilmington, we can quickly find specimens to observe.

     So, grab your walking sticks, and let's hike!

 

Easy to find garnet in host rock, BCSP
(Photo by Ken Casey)

 

     

What's in a name?   

 

     Garnet = Pomegranate?  A curious reference.  According to wikipedia.org, “[t]he name "garnet"
comes from the
Latin granatus ("grain"), possibly a reference to the Punica granatum ("pomegranate"),
a plant with red seeds similar in shape, size, and color to some garnet crystals.”

  (Source: http://en.wikipedia.org/wiki/Garnet)

 
Pomegranate in cross-section   Small garnets in situ from Brandywine Creek State Park
Photo by Peter (Fir0002), wikipedia.org   Photo by Ken Casey

     Much of Delaware garnet is a variety called “Almandine”.  “The name Almandine is a corruption of
Alabanda, a region in Asia Minor where these stones were cut in ancient times.”

  (Source: http://en.wikipedia.org/wiki/Garnet)

     “Almandine, also known incorrectly as almandite, is a species of mineral belonging to
garnet Group. The name is a corruption of alabandicus, which is the name applied by
Pliny the Elder to a stone found or worked at Alabanda, a town in Caria in Asia Minor.”

  (Source: http://en.wikipedia.org/wiki/Almandine) 

 

German: Almandit
Spanish: Almandita
Middle English: Alabandyne, Alabandine
Late Latin: Alabandina
Ancient Greek: Alabandicus
  (Source: http://www.thefreedictionary.com/almandite

    Greek mythology and historical accounts document its use as a gemstone and abrasive.  In such
literature, garnet is steeped with cultural references, from whence we derive its modern name.

  (Source: http://www.jewelrysupplier.com/2_garnet/garnet_mythology.htm

     The name “garnet” was grandfather prior to 1959 by the IMA.

     Just for the sake of demonstration here (and fun), I’ll bring the pomegranates for our snack.

 

 

Chemistry & Science

     Delaware's garnet is mainly Almandite.  Almandite is an iron-rich nesosilicate of chemical formula
Fe3Al2(SiO4)3
. It shares a solid solution series with Pyrope, having formula: Mg3Al2(SiO4)3. That
means that at some time during its formation, Iron can replace Magnesium, or vice-versa.

     Almandite is the harder of the two. On the Moh’s Hardness Scale, it ranges from 6.5-7.5. It’s relative
hardness makes it ideal for commonly found abrasives, as are used on a simple sheet of everyday
sandpaper.

     
Garnet sandpaper    60-Grit Garnet sandpaper   Garnet used to make sandpaper 
Photo courtesy of Grimes Industrial    Photo courtesy of Woodzone   Photo by Ken Casey 

   

  Though modern garnet sandpaper is manufactured by crushing larger garnet crystals, let
us not forget the garnets that make their way into sand via erosional processes.  Before sandpaper,
garnet sands were used.  Without being abrasive, might I suggest that we can still use
sediments and rocks as tools to learn about paleo-environments, as "[s]edimentary Rocks
preserve the record of the earth's ancient surface environments, and of life."

  (Source: http://www.uwgb.edu/dutchs/EarthSC102Notes/102ROCKS.HTM

     In the photos below, garnets are likely to be found in the river or run sediments, but not in
the Devonian rock above the road here at Red Hill.  As the Appalachian mountain chain is a mish-
mash of preserved geology and currently weathering outcrops, two significant anciently-captured
environments can lay side by side for us to see: crystalline mineral beds and sedimentary fossil
strata.

         
 Photos of Appalachian mountains and plateaus overlooking Susquehanna River at Red Hill, Hyner, PA  (Photos by Ken Casey)
 

     Delaware has a similar surficial geology boundary: crystalline Piedmont (to the west) and
some Chesapeake Group's fossil-bearing marine sediments (to the east), albeit of differing
(yet analagous) eras.  Its crystalline Lower Piedmont is of most interest to us here.

     Garnets are useful indicators to geologists to determine both the metamorphic facies and
paragenesis of rocks. It’s slow rate of elemental diffusion, relative to other indicator minerals,
aids scientists in the determination of the temperature-time history of the host rock.

  (Source: http://en.wikipedia.org/wiki/Garnet

         What can metamorphic garnet tell us?  Generally, its composition and texture tell all. Chemical composition alludes to its original rock type.  Mineral composition of its assemblage denotes temperature and pressure conditions of its formation.  And, texture observations speak to its degree of change.

(Source: http://www.uwgb.edu/dutchs/Earth
SC102Notes/102ROCKS.HTM)

Garnet-laden drill core samples
(Photo courtesy of Oliver Holm, Geoscience Australia)

     For example, one can correlate thermobarometry and microthermometry data from individual
mineral grains in an array of samples to determine the extent of metamorphic events.  As most
garnets studied are metamorphic, we know we can find this type at sites of orogenic changes,
or mountain-building events. So, let's study our local foothills and mountains.

     Our Piedmont province was originally formed by the Taconic Orogeny, during the Middle
Ordivician.  Several intervals of mountain-building occurred since then, until the most recent
Appalachian (or Alleghanian) Orogeny about 300 mya in the Carboniferous Period.

  (Source:  http://en.wikipedia.org/wiki/Appalachian_orogeny

                                        Geologic Time Scale (USGS)

     Therefore, in this highly active area of geology change, garnets form, are eroded into
sediment, an have formed again in various events over millions of years.  Our garnet-rich
geology plays host to much scientific study.  (Garnetology, anyone?)

     So, knowing our garnets can help us to identify and understand our local mineral assemblages.

            Garnet       Almandine       University of Delaware Garnet virtual tour

 

Some Delaware Garnet Geology

     Gneiss is the primary rock type which hosts garnets. From microscopic dodecahedral crystals
to macroscopics the size of a dime, these metamorphic dark-red silicates may be found in our area.
(Since geology knows very few political boundaries, the formations in which garnet occurs at the surface
stretch into nearby Pennsylvania and surrounding states, as well.)

   
Almandite Garnet crystal Photomicrograph, South Carolina's Appalachian Piedmont    Almandite Garnets the size of dimes in matrix,
Brandywine Creek State Park 
Photomicrograph by Harmon Maher ; Photo by Ken Casey 
 

     The smallest grained gneiss is best viewed under a microscope from a fresh core sample. For
example, they are within documented survey materials collected by the Delaware Geological Survey.
The largest may be perused upon by us on our hike to small outcrops and streambeds in our local parks.

   

     Our eastern Piedmont runs northeast-southwest, the entire length of the middle-Atlantic coastal area, intersecting at nine states and the District of Columbia. So, of course, similar garnet occurrences can be found in other states. Our region is marked with outcrops, exposing a modest wealth of garnet viewing areas. We will concentrate on our area’s Wissahickon Formation and Wilmington Complex of rocks.

 

Generalized Piedmont Map; Piedmont is Tan 
(Courtesy of Karl Musser, Cartographer, wikipedia.org

 

 
     According to DGS publication Delaware Piedmont Geology by Margaret O. Plank and William S. Schenck, “[m]ost Piedmont garnets are a dark-red, iron-rich variety called almandine. They usually occur as 12-sided crystals that vary in size from crystals so small they can be seen only under a microscope to crystals of an inch or more across. Garnets are considered semi-precious stones, but in the highly deformed rocks of the Piedmont they are usually fractured and not suitable for jewelery. Garnet is also used as an abrasive.”

  (Source:  http://www.udel.edu/dgs/Publications/pubsonline/SP20.pdf
)

 

   

     More specifically, Delaware garnets can vary in grain size and degree of metamorphism, to which
one could study for a long time, hence this article. For example, Delaware “[g]neiss is a course-
grained rock commonly having imperfect, but prominent light-dark layering. In the Delaware Piedmont
the light layers are composed of feldspars and quartz and the dark layers of mica, garnet, sillimanite,
amphiboles, and pyroxenes. Gneisses are formed by the high-grade metamorphism of either igneous
or sedimentary rocks."

  (Source: http://vulcan.wr.usgs.gov/LivingWith/VolcanicPast/Places/volcanic_past_delaware.html)

     A rare igneous garnet is found in the pegmatite of the Woodlawn Quarry.  The locale may be found
in the red area of the Generalized Geologic Map of Delaware, below.

    Why not try this one: Woodlawn Quarry: A GeoAdventure in the Delaware Piedmont

 
                   Generalized Geologic Map of Delaware, courtesy of the Delaware Geological Survey
                       Prepared by: Nenad Spoljaric and Robert Jordan, Revised by: Thomas E. Pickett

 
Physiographic Map of Pennsylvania, Pennsylvania Geological Survey
 

Microscopic Garnet

 

     Yes, right in our clubhouse’s own backyard, garnets taunt us for our attention. In nearby
Brandywine Springs Park, tiny 1-2mm pink-purple garnet grains may be found in gneiss. No
collecting is allowed here, but some may be observed, if you know what to look for.

     
Nearly microscopic garnets at BSP    Close-up of tiny garnets at BSP 
Photos by Ken Casey 
 

     As BSP is adjacent to our clubhouse at Historic Greenbank Mill, and drilling studies have been
conducted near our main intersection at Price’s Corner, we can learn from work by the DGS here.
For example, a 66-foot core sample yielded a lithology of biotite gneiss. As a major mineral,
microscopic garnet was reported at a 1% mode.  A facsimile of the report is below:

 

     
 

University of Delaware
Delaware Geological Survey
Open File Report No. 38, June 1995
Data Report on Rock Cores from Red Mill Road, Harmony Road,
Prices Corner, and Newport, Delaware

DGS ID: Cc13-17 SAMPLE NO.: 24896 QUAD: WIS
FIELD NO.: S-8-1 DATE ENTERED: 3/3/93
LOCATION: Prices Corner - core, 66' (58' ASL)
ROCK UNIT: Wilmington Complex ORIENTED SEC.:
STAINED: K-feldspar: Y Plagioclase: Calcite: Cordierite:
LITHOLOGY: Biotite gneiss
MAJOR MINERALS MODE (%) ACCESSORY MINERALS

quartz 38.0 zircon, apatite
plagioclase 38.0 monzanite halos in biotite,
biotite 22.0 colorless to yellow
garnet 1.0
opaques 1.0 RETROGRADE MINERALS
sillimanite mats x
                Pale green mineral with opaques

NUMBER OF POINTS COUNTED: 400
COMMENTS
The rock in this core is a fine-grained dark biotite gneiss with biotite grains aligned vertically.

FABRIC AND TEXTURES

Plagioclase: Equant xenoblastic grains, partial twinning, round inclusions of quartz and plagioclase
Quartz: Undulatory extinction; large subgrain boundaries with lobate edges
Biotite: Pleochroism is light brown to dark brown; laths have a preferred orientation and are aligned to define the foliation
Garnet: Tiny xenoblastic to subidioblastic garnets grow over other grain boundaries; some with small inclusions of opaques; one garnet is elongated in the foliation
Opaques: Irregular shapes; two different opaques; in reflected light, one is dark and the other is silver

 
     
 

    The fabric and textures noted in the rock core of sample 38 contain garnets as: “Garnet: Tiny xenoblastic
to subidioblastic garnets grow over other grain boundaries; some with small inclusions of opaques; one
garnet is elongated in the foliation”

  (Source: http://www.udel.edu/dgs/Publications/pubsonline/report38/31.html

 

 

xpl off of 1 edge of Garnet 10* (Almandite crystal thin-section)
(Photomicrograph by UCLA's Petrographic Workshop)
 

     If you like the smaller end of the garnet grain range, then these are the specimens for you.

 

Macroscopic Garnet

     If, on the other hand, you prefer to view larger garnets in the field, we’ll pay a brief visit to the defunct
Woodlawn Quarry, also in northern Delaware. Now a wildlife refuge with hiking trails, one can still find the
occasional surface rock. No collecting is generally allowed here, so please enjoy nature. Perhaps now is
a good time to take our morning break, while some of us photograph a specimen or two. Let’s focus upon
a description before clicking our shutters.

     
Close-up of 3mm Garnet crystal in graphic granite, Woodlawn Quarry    Garnet in Graphic Granite (Feldspar, Quartz, Muscovite), Woodlawn Quarry 
Photos by Ken Casey 
 

     As a general description of garnets here, the DGS’s Woodlawn Quarry GeoAdventure states that,“[g]arnet
occurs here as tiny dark red crystals with 12 sides, called a dodecahedron. The crystals are rare and small
and it is necessary to look carefully to find crystals. The garnets are hard, have a glassy luster and no distinct
cleavage. When broken they look like dark red glass.”

  (Source: http://www.udel.edu/dgs/Education/woodlawn.html

     Garnet crystals here occur in granite pegmatites, along with feldspar, mica, quartz, and beryl.  That's all
the garnet we'll see here; so, take your last photos and field notes, please.

     Mount up, everybody. It’s time for the climax of our virtual fieldtrip: our visit to Brandywine Creek State Park!
Here is where the largest garnets may be found. We will soon feast our eyes on a few of these lithic beauties.

     We can actually hike from Woodlawn downhill to BCSP. Then, voila, we’re there. Fast, healthy, and little
carbon emissions. Let’s pause for a quick drink for hydration, before we take in the park’s garnetous splendor.
 

BCSP Entrance sign on SR-92   Thompson's Bridge near BCSP entrance   Trailhead bridge at BCSP
Photos by Ken Casey

     Note the slow, yet steady, moving Brandywine Creek. It is home for wildlife, such as ducks, geese, fish,
and a variety of water plants. Feeding into the creek are smaller streams, called “runs”. These runs are where
we will find our garnet-laden rocks. So please, tread lightly, as we traverse the woods, through the sticker
bushes up to the smaller waterway’s edge.

  Netscape users just click on picture to activate your Media Player (.AVI, 2MB)
Delaware Greenway sign, BCSP  Rocky Run video with garnet rocks 
Photos and video by Ken Casey 
 

     As the Delaware Greenways Project expands, we’ll be able to hike directly to other geologic locations
rather efficiently on future MOTM fieldtrips. Thanks to the State of Delaware and its partners, our educational
and recreational experiences will be enhanced.

     Now, to the park-at-hand. Follow me.  I’ll guide us with the DGS's GeoAdventure directions, so that we
may tread lightly, and leave the squirrels and woodpeckers to their business.  Don't worry, we'll see garnets!

     Our hike has brought us downhill along SR-92S, then we took a breather in the parking lot, near the park
entrance sign.  As we face the trailhead, look up the hill to our left.  We will see trees and shrubs
growing over moss and fungus covered boulders.  Many of these rounded remnants are filled with
discernable garnets.  Let's take a closer look.

     
Rock outcrop, west of Rocky Run, BCSP    Heavy garnet-laden boulder at BCSP entrance field    Another garnet-filled boulder at BCSP 
Photos by Ken Casey 
 

     Next, we'll hike about 100 yards to “[c]ross the boulder field, turn left, and walk toward Rocky Run.
Look for a wall of rock bordering the northwest side of Rocky Run (D, Figure 2). Wissahickon rocks
form the wall and the streambed while the rounded boulders of Wilmington Complex gneisses clog the
stream, litter the southeast banks and lie scattered in the flood plain. The layering in the Wissahickon
wall rock is irregular and defined by stringers of garnet, biotite and sillimanite in a mass of quartz and
feldspar. The garnets are dark red, either oval or round, and may be as large as three quarters of an
inch in diameter. The stringers, and any folds that are present, are best seen by standing in the stream
and looking upstream. The contact between the Wissahickon and Wilmington rocks is hidden beneath
the flood plain.

Rocky Run at BCSP    Boulder field at Rocky Run, BCSP    Close-up of garnets in matrix 
Photos by Ken Casey 
 

     "To see the contact, you need to follow the stream to the confluence of Hurricane Run and Rocky Run
and stay on the northeast side of Rocky Run. (E, Figure 2). The exposed contact is difficult to recognize
and probably interesting only to geology students at the high school or college level. It is exposed in a ten
foot area along the northeast side of Rocky Run where dark, fine grained Wilmington Complex gneisses are
interlayered with light colored Wissahickon gneisses. The Wissahickon rocks appear to have been melted
and recrystallized to form granites with thin layers of garnets. The biotite and sillimanite that occur in the
Wissahickon gneisses are replaced by tiny garnets. This reaction in which garnet replaces biotite and
sillimanite occurs only at very high temperatures. The Wilmington Complex layers vary in thickness between
3 inches and 2 feet, and are dark solid, massive rocks.”

  (Source:  http://www.udel.edu/dgs/Education/bluerocks.html

     Let's zoom in on our gneiss garnets. 

         
Large red garnets in Rocky Run rock, BCSP    Closer view    Closest view 
Photos by Ken Casey 
 

Other Garnet Experiences

     Now that we have sampled views of some of the largest garnets in Delaware, let's have lunch.  I'll trade
you an extra pomegranate for half of your peanut butter and jelly sandwich.  We can discuss other garnet
experiences over dessert, if you like. 
 

     Of course, our club visits collecting sites for garnet all around our area. Please do inquire upon how to
join us as members, and can benefit from our club fieldtrips. Our trips our setup and led by our own Bob Asreen,
Geologist, and Vice-President of Fieldtrips.

 



(Top): Gem Trails cover by Mark Webber








(Right): Close-up of Wissahickon Valley garnets in schist matrix from Fairmount Park
 

     Gem Trails of Pennsylvania and New Jersey by Scott Stepanski and Karenne Snow, suggests that very small, nicely faced, and deep red Almandine garnets may be found weathered out of their host schist at Fairmount Park, Philadelphia. This author visited there about three years ago, and found small quantity on the trail--enough to fill a thimble or two.

     I was fortunate enough to meet Ms. Snow a couple of years ago at one of the Cape-Atlantic Rockhounds events.  She was kind enough to sign my copy of her book.  I think it brought me luck, since I've had some good experiences collecting from locations that she and Scott Stepanski had recommended.

     These Wissahickon Valley garnets may be collected from Fairmount Park in Philadelphia. According to the book, garnets wash out of the surrounding schist, to be collected on the trail. 
Good Luck!

 
 
 

    

     If you wish an educational experience for your family, ages 6-8, from one our local nature groups, try:

Delaware Nature Society Digs:  Ages 6-8 + Parent

Mining and Minerals
Course #: S07-056-AS Max: 13
Date: Sunday, March 25 Time: 2:00-4:30pm
Member Price: adult $9, child $7
Nonmember Price: adult $13, child $10
Led by David Pragoff
Dig for mineral treasures including mica, quartz, and garnet at a unique feldspar quarry near the Brandywine
River. Learn why these minerals are here and how they were mined. Bring your rock hammer or borrow ours
as we head out on a "rock-ing" mining expedition. Van transportation provided to the nearby site. Parent
participation required.”

  (Source: http://www.delawarenaturesociety.org/edu/ash_win07.html

Though this information was for a past dig, just click on the weblink for new digs.

    

     As a side note and segue way into a future MOTM, I’ll mention that garnet was discovered at the now
closed Brandywine Quarry in Wilmington by Fred Hilbiber in 1924, according to the Mineralogical Record. 
It is associated with two exotic minerals, Canbyite and Hisingerite--both found in Delaware.  (see: below)

     Are there two sides to the same mineral?  Stay tuned!

Mineralogical Record

Volume 9, pages 1-5, 1924

CANBYITE, A NEW MINERAL

A. C. HAWKINS and EARL V. SHANNON, Rochester, N. Y., and Washington D.C.

OCCURRENCE.

Some thirty-five or forty years ago, when the Brandywine Quarry at Wilmington, Delaware, was in operation, Mr. Fred Hilbiber, then living in that city, discovered in this quarry the minerals here described. The quarry is located a quarter mile northwest of the Baltimore and Ohio Railroad bridge on Brandywine Creek. It is at present used as a storage yard adjacent to a leather manufacturing plant.

The country rock is a gabbro, containing numerous quartz stringers and masses due to the effects of intrusive granite, and showing the minerals enumerated below. The minerals associated with the canbyite are as follows:

Bornite: pure masses, iridescent, weighing altogether several pounds.
Chalcopyrite: alone, and associated with bornite and pyrite.
Chalcocite: associated with garnet and hisingerite.
Pyrrhotite: narrow stringers associated with other sulphides.
Pyrite: brilliant simple cubes, 1 to 3 mm. in diameter.
Marcasite: coating surfaces of the rock, decomposing rapidly on exposure.
Garnet: fibrous crystalline crusts associated with hisingerite.

  (Source: http://www.minsocam.org/msa/collectors_corner/arc/canbyite.htm)  

 

    

Two Museums of Note

     Our MOTM format will continue to offer us information on two places we can visit to learn more
about minerals, such as this month's "garnet".  One includes an online museum, the other offers a
book that represents its collection.  Both support a real place that you can physically visit, if you like.

     Hmmm! Who has a collection of garnets for viewing? Well, the University of Delaware Mineralogical
Museum has it’s virtual mineral tour online of Minerals on Display. Some representative garnets are housed
therein. Why not take a gander?

     “Everything’s big in Texas“, goes the unofficial motto. The Houston Museum of Natural Science, located
in Houston, Texas, has a large, world-renowned rock and mineral collection to back up that claim. They
currently do not have an online photo gallery, but if you visit in person, I’m told you won’t be disappointed.
The museum has just published a photo book of it’s treasured collections, titled
Masterpieces of the Mineral World
by Joel A. Bartsch, Mark Mauthner, and Wendell E. Wilson. You can order it online or via phone to view at home.

 

Uses

     Delaware garnet generally has no actual industrial or lapidary use.  If it were found in sufficient
quality and quantity, perhaps our almandite can be employed as an abrasive material or as a water
filtration medium. 

     It does have use for scientists as an indicator mineral for the geologic study of our area.  And,
of course, collectors and nature observers, such as us, can enjoy its beauty and scientific interest.

 
Exposed garnets from Brandywine Creek State Park, 2004
Perhaps by now, they are eroded out--who knows?
(Photo by Ken Casey)
 
 

Links

 

Pyroxenes (and amphiboles), Tourmaline and Garnet (UC Berkeley)

Woodlawn Quarry: A GeoAdventure in the Delaware Piedmont

http://bulletin.geoscienceworld.org/cgi/content/abstract/70/11/1425

http://webmineral.com/data/Almandine.shtm

http://www.rbmason.ca/databank/mineral/garnet.html

Delaware Minerals List at mindat.org

 

Members' Gallery

     Here is where DMS Members can add their Delaware Garnet photos to share with us.

     Arthur Koch has a treat for us--photos of some of the largest, sharpest Delaware garnets. 
These are from his personal collection.  And, he is the photographer.  Thanks, Arthur!

     Arthur earned his Bachelors of Science degree in Geology, and field collects rocks and
minerals.  I believe he is also a part-time mineral dealer, as well. 

     To learn more about Arthur and his garnets, visit his photo gallery at mindat.org

     These four specimens are from the defunct Woodlawn Quarry, Wilmington, Delaware. 

 
Almandine on Muscovite, crystal 2.4 cm x 2.0 cm

  Almandine crystal, 2.6 cm x 2.1 cm
 
Almandine on Muscovite, crystal 2.9 x 2.1 cm   Almandine crystal, 1.5 cm x 1.3 cm

 

Until Next Time

     We hope you have enjoyed our historic visit to Delaware Garnet.  Please join
us next month, for another article, and we shall journey together!

    
Until then, stay safe, and happy collecting. hardhat2a.gif (5709 bytes)

 

 

Article Contributors

 

wikipedia.org

Delaware Piedmont Geology by Margaret O. Plank and William S. Schenck, DGS

A. C. HAWKINS and EARL V. SHANNON, Mineralogical Society of America's Mineralogical Record

 

Photo & Graphics Credits

    I would like to gratefully acknowledge the generous contributions of our fellow Delaware
Garnet enthusiasts, collectors, authors, curators, professionals, and club members who
made this work possible. 
Thanks.

Arthur Koch, DMS Member, B. S. in Geology, Mineral Photographer

Marchex, Inc., World Flag Database

wikipedia.org

Peter (Fir0002), wikipedia.org

Grimes Industrial 

Woodzone

Oliver Holm, Geoscience Australia

Harmon Maher, Professor of Geology, University of Nebraska-Omaha

Courtesy of Karl Musser, Cartographer, wikipedia.org

Delaware Piedmont Geology by Margaret O. Plank and William S. Schenck, DGS

Nenad Spoljaric and Robert Jordan, Thomas E. Pickett, Delaware Geological Survey

Physiographic Map of Pennsylvania, Pennsylvania Geological Survey

Photomicrograph by UCLA's Petrographic Workshop

Gem Trails cover by Mark Webber



2007 All contributions to this article are covered under the copyright protection of this article
and by separate and several copyright protection(s), and are to be used for the sole purposes of
enjoying this scholarly article.  They are used gratefully with express written permission of the
authors, save for generally-accepted scholarly quotes, short in nature, deemed legal to reference
with the appropriate citation and credit.  Reproduction of this article must be obtained by express
written permission of the author, Kenneth B. Casey, for his contributions, authoring, photos, and
graphics.  Use of all other credited materials requires permission of each contributor separately.
Links and general contact information are included in the credits above, and throughout this article.
The advice offered herein are only suggestions; it is the reader's charge to use the information
contained herein responsibly.  DMS is not responsible for misuse or accidents caused from this
article. All opinions, theories, proofs, and views expressed within this article, and in others on this
website, do not necessarily reflect the views of the Delaware Mineralogical Society. 


Suggested Reading:

Delaware Piedmont Geology including a guide to the rocks of Red Clay Valley
by Margaret O. Plank and William S. Schenck

Gem Trails of Pennsylvania and New Jersey by Scott Stepanski and Karenne Snow

 

KEN.JPG (31503 bytes)

   About the Author:  Ken is current webmaster of the Delaware Mineralogical Society.  He has a diploma in Jewelry Repair, Fabrication & Stonesetting from the Bowman Technical School, Lancaster, PA, and worked as jeweler.  He has also studied geology at the University of Delaware.  And, he is currently a member of the Delaware Mineralogical Society and the Franklin-Ogdensburg Mineralogical Society.  E-mail: kencasey98@yahoo.com.


Invitation to Members

Members,

Want to see your name in print?  Want to co-author, contribute, or author a whole Mineral of the Month article?  Well, this the forum for you!

And Members, if you have pictures, or a story you would like to share, please feel free to offer.  We'd like to post them for our mutual enjoyment.   Of course, you get full photo and author credit, and a chance to reach other collectors, hobbyists, and scientists.  We only ask that you check your facts, give credit where it is due, keep it wholesome for our Junior Members watching, and keep on topic regarding rockhounding.

You don't even have to be experienced in making a webpage.  We can work together to publish your story.  A handwritten short story with a Polaroid will do.  If you do fancier, a text document with a digital photo will suit, as well.   Sharing is the groundwork from which we can get your story out there.

Our club's webpages can reach any person surfing the net in the world, and even on the International Space Station, if they have a mind to view our website!

We are hoping for a possible tie-in to other informative programs upon which our fellow members might want to collaborate.  Contact any officer or board member with your suggestions.

Our next MOTM will be a surprise.  For 2007-8, we are waiting for your suggestions.  What minerals do you want to know more about?

aniagate.gif (1920 bytes)

____________________________________

Most of the Mineral of the Month selections have come from most recent club fieldtrips and March Show Themes, and from inspriring world locales, and suggestions by our members, thus far.  If you have a suggestion for a future Mineral of the Month, please e-mail me at: kencasey98@yahoo.com, or tell me at our next meeting.

 

 

Past Minerals of the Month
August 2007 Mineral of the Month: Schorl (Black Tourmaline)
July 2007 Mineral of the Month: Rubellite
June 2007 Mineral of the Month: Elbaite 
May 2007 Mineral of the Month: Delaware Feldspar, Part 2 
April 2007 Mineral of the Month: Delaware Feldspar: Orthoclase
March 2007 Mineral of the Month: "The Colors of Fluorite"
February 2007 Mineral of the Month: Pennsylvania Fluorite
January 2007 Mineral of the Month: Sillimanite
December 2006 Mineral of the Month: Hedenbergite by Karissa Hendershot
November 2006 Mineral of the Month: Brandywine Blue Gneiss
October 2006 Mineral of the Month: Spessartite by Karissa Hendershot
September 2006 Mineral of the Month: Native Silver
August 2006 Mineral of the Month: Kryptonite
July 2006 Mineral of the Month: Azurite
June 2006 Mineral of the Month: Pyromorphite
May 2006 Mineral of the Month: Tsavorite by Karissa Hendershot
April 2006 Mineral of the Month: Variscite
March 2006 Mineral of the Month: Petrified Wood, Part II
February 2006 Mineral of the Month: Petrified Wood, Part I
January 2006 Mineral of the Month: Strontianite by Karissa Hendershot
December Mineral of the Month: Clinozoisite
November Mineral of the Month: Bismuth
October Mineral of the Month: Wulfenite by Karissa Hendershot
September Mineral of the Month: Turquoise
August Mineral of the Month: Peridot
July Mineral of the Month: Ruby
June Mineral of the Month: Antarctic Fluorite
May Mineral of the Month: Dolomite, Part 2
April Mineral of the Month: Dolomite, Part 1
March Mineral of the Month: Calcite
February Mineral of the Month: Agate
January Mineral of the Month: Fluorite
December Mineral of the Month: Pyrite
November Mineral of the Month: Stilbite  
October Mineral of the Month: Celestite   

 

Comments and questions: kencasey@delminsociety.net

This page last updated:  February 19, 2011 10:14:50 AM

 

       

  


Next Meeting
 

April Program, Monday, April 8, 2013:

"Destruction of the Fossil Exposures in the Chesapeake Bay Area" presented by Dr. Lauck Ward

General Club Meeting:
April 8, 2013
(Monday)

We are meeting at
Greenbank Mill


Special Meetings:
 

*Show Committee Meeting, April or May, 2013

*New Home/Lapidary Committee, 2013

*Board Meeting,  April, 2013

Next Field Trips
 

Fieldtrips!

Past Fieldtrips
 

Next Show
DMS March Show
March 1-2, 2014 at DelTech Stanton

 


Our 2013 Show Theme was:
"All That Glitters is as Good as Gold!"

March Show 2013 Report

Updates!

 

 

 
Articles

 

Fossil Forum


"Dinny, the Dino"

"Belemnites are coming"

 

MOTM June also commemorates our 50th Show!

It's shiny, yellow, and is a symbol of 50 Years!Can you guess?

Past MOTM

Collecting Adventure Stories:

"Sunny Brook Crick Goethite" by Joe Dunleavy