RockHoundBlog

Fossil Amber or Fossil Resin

Filed under: regular postings — Gary July 16, 2010 @ 10:19 pm
frog_in_amber

frog_in_amber

Amber is the popular name for fossilized resin of botanical origin. The proper scientific terminology is fossil resin, but we will use the terms amber and fossil resin interchangeably. The word amber also denotes a golden color that amber predominately reflects (recall that when human eyes see color, it is actually the portion of the visible light spectrum that an object reflects that is detected). In fact, amber reflects many frequencies of light, including red, green and blue that together constitutes the entire visible spectrum. Archeological findings show that amber was one of the first materials prehistoric humans used for ornamentation, with instances dating back as far as 30,000 years. Use of fossil resin for jewelry and other decoration continues unabated, and amber is often considered as a gemstone.

Amber is also valued for its botanical and animal inclusions that are trapped by the sticky resin as it flows as sap, which is also organic. Of course, other life is captured including microscopic bacteria that often produce gas bubbles, and various fungi. Both the botanical and animal inclusions not only add beauty, but also are of potential scientific value in the study of taxonomy and evolution. Animal inclusions are usually invertebrates, specifically arthropods, and only extremely rarely a vertebrate such as a tiny lizard. Fossil resin inclusions are predominately insects, which should be no surprise since botanical resin is an evolutionary adaptation of plants that is, in part, for protection against insects.

Fossil Amber Chemistry
Fossil resin’s molecular constituency is mainly carbon and hydrogen atoms that readily form hexagonal rings. Molecular bonding between the rings increases over time (called polymerization), and the sticky resin becomes hard. There are other types of atoms in trace to larger amounts that alter physical properties and may be substrates to certain organic solvents. For all practical purposes, the hardened resin, or amber, is a “plastic”. Just when the resin becomes amber, or a fossil, is not defined, and is perhaps not definable. It is even contentious, since fossil resin is a commercial product in a competitive market. Younger amber is often called copal, though it is essentially as hard and its physical properties differ little from older resins.

All fossil resins are substrates for both hydrophilic (e.g., alcohol or acetone) and lipophilic (e.g., benzene) organic solvents and will disolve in them. The solvents will create various weak chemical interactions with the resin in order to solubilize it. The most common of these interactions are the relatively weak van der Waals interactions (induced dipole interactions), the stronger dipole-dipole interactions, and the even stronger hydrogen bonds (interaction between O-H or N-H hydrogens with O or N atoms).

Diamonds (and most mineral based gems) are forever, but fossil resin (amber) is not. As an unstable organic polymer, amber is biodegradable, just like a plastic milk jug or fiberglass boat. Its many weak covalent bonds and weaker hydrogen bonds are easily broken, a process that is accelerated by electromagnetic radiation of all frequencies and heat; ultraviolet is especially damaging (do not expose amber to sunlight), while visible and infrared much less so. Thus, while amber is, in a sense, the perfect preservative of fossils, once removed from the environment in which it formed, it is destined to crumble into dust; the time is long compared to the human lifespan, but essentially instantaneous on a geological timespan. Diamonds, on the other hand, go on forever.

Amber, Natural Selection and Chemical Warfare
Fossil resin (a.k.a., amber) is the result at least in part of nature’s oldest drama, predator versus prey. Science does not yet know when it appeared in the Kingdom Plantae’s arsenal of survival tactics, but natural section has conserved and probably diversified its usage. In temperate climates, the pines are prodigious producers of resin, which is used to make turpentine. In tropic climates, the genus Hymenaea, a timber tree, is the prolific producer. The evolutionary advantages of resin are varied. The resin is exuded to seal wounds such as from wind, fire, lightening or insect predation. Resin also contains a diversity of chemical defensive weapons. Some of these repel insects, and others attract insects that attack harmful insects, or attract parasites of insects that attack the plant, or are toxic to harmful fungi; in short a diverse chemical arsenal.

A Container for the whole Tree of Life
In terms of the Tree of Life, amber is most interesting since it entombs all three domains, Arachaea, Eubacteria and Eukarya. Archaea and eubacteria microbes are, of course, everywhere and surely embedded in the amber at high density. Interestingly, it is possible that some microbes. Still controversial finding a decade old claims to have recovered from the gut of a Hymenoptera from 30 million year old Dominican amber some three-dozen species of bacteria from ancient spores that grew on culture plates. The bacteria are from the extant genus Bacillus, a group that go dormant forming spores. Interestingly, Bacillus thuringiensis is used in the biological control of insects. Bacillus thuringiensis parasitizes the caterpillars of some harmful moths and butterflies. Spraying or dusting plants with its provides some protection against gypsy moth, tent caterpillar, and the tobacco hornworm. The bacteria has a gene that produces a toxic chemical warfare. The gene for this toxin has also been introduced into some crops.

Fossil Amber Ecosystems
One way to view amber is as a sealed unit containing a cross section of an ancient ecosystem with all its intricate predator-prey as well as beneficial symbiotic systems (e.g., termites as the methane produced by symbiotic bacteria that digest fiber in the termite gut). Fossil resin is a superb preservative, with organisms such as insects and spiders preserved in full three-dimensionality and in living color. To some degree, even, nucleotide sequence from ancient DNA is preserved, although resurrection of a Jurassic dinosaur is clearly science fiction.

Spider_in_Amber

Spider_in_Amber

Amber’s Geographic Dispersion
Amber comes from throughout the world, even the Arctic. However, in terms of commercial availability, the Baltic area of Europe produces vast amounts, followed by the Dominican Republic in a distant second, with minor amounts coming from Central and South America, and more specifically, Mexico and Colombia, respectively. Amber from other localities is miniscule.

Baltic Amber
An enormous amount of fossil resin is extracted on the shoreline of the Baltic Sea, and these strata are dated to be Eocene in age, give or take a few million years, thus making it some of the oldest amber that is available in commercial quantity. The largest Baltic amber mine is in Kaliningrad, Russia, but Baltic amber is also found in Lithuania, Latvia, Estonia, Poland, Russia, and sometimes washes ashore far away in Denmark, Norway, and England. Fossil inclusions are relatively rare, almost always in isolation and usually tiny, and the amber is normally occluded with botanical debris and bubbles; for this reason, fossil specimens are best made viewable in pieces cut to small size prior to polishing, and pictures many times require a trinocular microscope.

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Bancroft-Mineral Capital of Canada – 47th Annual Rockhound Gemboree

Filed under: regular postings — Gary July 15, 2010 @ 9:59 pm


Bancroft Rockhounding

47th Annual Rockhound Gemboree

Dates: Jul 29, 2010 to Aug 1, 2010
Location: North Hastings Community Centre & Bancroft Curling Club
Website: www.bancroftdistrict.com
Phone: (613) 332-1513
Canada’s Largest Gem and Mineral Show.

July 29th 2010 until August 1st 2010

Head to the “Mineral Capital of Canada” July 29, 30, 31st, and August 1st for the 47th Annual Rockhound Gemboree, chosen to be one of the top 100 Festivals & Events in Ontario in 2009. Canada’s largest gem & mineral show brings together over 110 dealers of fine mineral specimens, gemstone jewellery, and lapidary supplies. Highlights include a gold panning booth, rock and mineral talks with geologists from Natural Resources Canada, a swapping area, a mineral display and expert mineral identification services offered by Malcolm Back of the Royal Ontario Museum, and geologist-led mineral collecting field trips.

Gore Mountain Garnet Mines, North River, New York

Filed under: Rockhound Travel — Gary @ 9:22 pm
Garnet Mine

Garnet Mine

The hardest garnet in the world is only found on Gore Mountain, making the garnet extremely rare. The Barton garnet has an unusual and beautiful ruby red color that flashes in the sun. In 1969, the Governor of New York, Nelson Rockefeller, made the Barton garnet the New York State Gem Stone.

Garnet Prices

Garnet Prices

They also offer an online coupon that you can print off.  Click the image for the actual coupon to print.

RockHound Coupon

RockHound Coupon


  1. One of the World’s largest garnet deposits
  2. Largest garnet crystals in the world
  3. Source for the New York State Gemstone & the January birthstone… Garnet
  4. Oldest family owned and operated mine in the United States
  5. ANYONE can find a gem quality garnet without using tools
  6. Located in the scenic Adirondack Mountains, 2400 feet above sea level
  7. Fantastic panoramic views over the Adirondack Park
  8. Easy access… drive right into the old mine site
  9. Catering to the bus tour companies for over 30 yearsHandicap  Accesible
  10. Garnet mine tour business started in 1933
  11. Gore Mountain garnet deposit is recognized as a world famous geology site
  12. Mine site is flat, making it good for walking and for wheelchair accessibility

gore_mountain_garnet

gore_mountain_garnet

Amphibole

Filed under: Mineral of the day — Gary @ 11:23 am
Amphibole (Hornblende)

Amphibole (Hornblende)

Amphibole (pronounced /ˈæmfɨboʊl/) defines an important group of generally dark-colored rock-forming inosilicate minerals, composed of double chain SiO4 tetrahedra, linked at the vertices and generally containing ions of iron and/or magnesium in their structures. Amphiboles crystallize into two crystal systems, monoclinic and orthorhombic. In chemical composition and general characteristics they are similar to the pyroxenes. The chief differences from pyroxenes are that (i) amphiboles contain essential hydroxyl (OH) or halogen (F, Cl) and (ii) the basic structure is a double chain of tetrahedra (as opposed to the single chain structure of pyroxene). Most apparent, in hand specimens, is that amphiboles form oblique cleavage planes (at around 120 degrees), whereas pyroxenes have cleavage angles of approximately 90 degrees. Amphiboles are also specifically less dense than the corresponding pyroxenes. In optical characteristics, many amphiboles are distinguished by their stronger pleochroism and by the smaller angle of extinction (Z angle c) on the plane of symmetry. Amphiboles are the primary constituent of amphibolites.

Amphiboles are minerals of either igneous or metamorphic origin; in the former case occurring as constituents (hornblende) of igneous rocks, such as granite, diorite, andesite and others. Those of metamorphic origin include examples such as those developed in limestones by contact metamorphism (tremolite) and those formed by the alteration of other ferromagnesian minerals (hornblende). Pseudomorphs of amphibole after pyroxene are known as uralite.

The name amphibole (Greek αμφιβολος – amphibolos meaning ‘ambiguous’) was used by RJ Haüy to include tremolite, actinolite, tourmaline and hornblende. The group was so named by Haüy in allusion to the protean variety, in composition and appearance, assumed by its minerals. This term has since been applied to the whole group. Numerous sub-species and varieties are distinguished, the more important of which are tabulated below in two series. The formulae of each will be seen to be built on the general double-chain silicate formula RSi4O11.

Chemical formulae

Orthorhombic series

  • Anthophyllite (Mg,Fe)7Si8O22(OH)2

Monoclinic series

  • Tremolite Ca2Mg5Si8O22(OH)2
  • Actinolite Ca2(Mg,Fe)5Si8O22(OH)2
  • Cummingtonite Fe2Mg5Si8O22(OH)2
  • Grunerite Fe7Si8O22(OH)2
  • Hornblende Ca2(Mg,Fe,Al)5(Al,Si)8O22(OH)2
  • Glaucophane Na2(Mg,Fe)3Al2Si8O22(OH)2
  • Riebeckite Na2Fe2+3Fe3+2Si8O22(OH)2
  • Arfvedsonite Na3Fe2+4Fe3+Si8O22(OH)2
  • Crocidolite Na2Fe2+3Fe3+2Si8O22(OH)2
  • Richterite Na2Ca(Mg,Fe)5Si8O22(OH)2
  • Pargasite NaCa2Mg3Fe2+Si6Al3O22(OH)2

Descriptions

On account of the wide variations in chemical composition, the different members vary considerably in properties and general appearance.

Anthophyllite occurs as brownish, fibrous or lamellar masses with hornblende in mica-schist at Kongsberg in Norway and some other localities. An aluminous related species is known as gedrite and a deep green Russian variety containing little iron as kupfferite.

Hornblende is an important constituent of many igneous rocks. It is also an important constituent of amphibolites formed by metamorphism of basalt.

Actinolite is an important and common member of the monoclinic series, forming radiating groups of acicular crystals of a bright green or greyish-green color. It occurs frequently as a constituent of greenschists. The name (from Greek ακτις/aktis, a ‘ray’ and λιθος/lithos, a ‘stone’) is a translation of the old German word Strahlstein (radiated stone).

Glaucophane, crocidolite, riebeckite and arfvedsonite form a somewhat special group of alkali-amphiboles. The first two are blue fibrous minerals, with glaucophane occurring in blueschists and crocidolite (blue asbestos) in ironstone formations, both resulting from dynamo-metamorphic processes. The latter two are dark green minerals, which occur as original constituents of igneous rocks rich in sodium, such as nepheline-syenite and phonolite.

Pargasite is a rare magnesium-rich amphibole with essential sodium, usually found in ultramafic rocks. For instance, it occurs in uncommon mantle xenoliths, carried up by kimberlite. It is hard, dense, black and usually idiomorphic, with a red-brown pleochroism in petrographic thin section.

Amphibole compositions

Amphibole compositions

Amphibole compositions in the system Mg7Si8O22(OH)2 (anthophyllite)–Fe7Si8O22(OH)2 (grunerite)–“Ca7Si8O22(OH)2.” The general compositional fields are outlined, and coexisting amphibole compositions are shown by tie lines between the actinolite field and the anthophyllite-grunerite field.

New York Rockhounding

Filed under: Great Finds-specimens — Gary @ 11:13 am

Check out the NY State Museum’s webpage on amphiboles:

Discovery of New Mineral Species

amphiboles

amphiboles

Click here for site

New mineral found in moon meteorite – hapkeite

Filed under: Great Finds-specimens — Gary July 13, 2010 @ 10:36 pm
hapkeite

A backscatter electron image shows the newly discovered mineral, known as hapkeite or Fe2Si, in orange. Another type of mineral, FeSi, is indicated as yellow.

WASHINGTON — A chunk of the moon that landed on Earth as a meteorite contains a new mineral, which scientists have named after a researcher who years ago predicted the unusual process that formed the material.

Grains of the material, made of iron and silicon, were found in pieces of a meteorite that was discovered in Oman on the Saudi peninsula, said Lawrence A. Taylor of the University of Tennessee, a member of the research team that reported the find.

The process that led to the material’s formation on the moon “is much different than anything we can imagine on Earth,” Taylor explained.

Small meteorites that would burn up in an atmosphere like Earth’s can crash into the moon because of its lack of an atmosphere. The mineral was found in a piece of the moon that had been large enough to make it through Earth’s atmosphere without being destroyed.

When that happens, Taylor explained, the impact creates heat that melts some of the rocks and forms a vapor that is deposited on nearby materials.

Mineral dubbed ‘hapkeite’
The process and discovery of the new material is reported in this week’s issue of Proceedings of the National Academy of Sciences.

Some iron-silicon minerals form on Earth, sometimes as a result of lightning strikes, but the new mineral is a different combination, Taylor said. Hapkeite has the chemical formula Fe2Si, indicating the presence of two atoms of iron to one of silicon.

The researchers named the new mineral hapkeite after Bruce Hapke of the University of Pittsburgh, who 30 years ago predicted the process that forms this mineral.

“I told them so,” said an amused Hapke, who added: “It’s quite an honor.”

He said he developed the theory to explain weathering of surface materials in space, a process that darkens the moon’s surface.

Lunar and terrestrial weathering
Weathering on Earth creates soil through the action of water, oxygen and organic processes. That can’t happen on a place without water or an atmosphere, so the darkening and breaking down of the surface rocks had to be explained in another way.

Benton C. Clark, a weathering expert at Lockheed Martin Corp., said the process of forming the moon mineral seems plausible, but stressed that it needs to be defined as “space weathering,” which would be unlike weathering on Earth.

“Naming a mineral after the outstanding scientist Bruce Hapke is a fitting tribute,” he said.

Robert Craddock, science adviser for the Smithsonian Institution’s undersecretary for science, said the paper explains some of the spectral measurements researchers read when they study airless planets. Measurements of the spectrum of reflected light are used to help determine the presence of minerals.

The newly found mineral, he added, is one of a number of minerals predicted as a possible result of space weathering.

Culver City Rock and Mineral Gem Show

Filed under: Coming Events — Gary July 4, 2010 @ 8:44 pm

Gems Show, Culver City, Fiesta of Gems

Featuring: The Wonderful World of JASPER

Saturday, July 10, 2010   10 am – 6 pm
Sunday,   July  11, 2010   10 am – 5 pm

Veterans Memorial Auditorium
4117 Overland Avenue

Culver City, California

Click here for map

Culver City Map

Culver City Map

The Fiesta of Gems will offer exhibits, demonstrations, children’s games, grab bags, door prizes and dealers offering rocks, minerals, fossils, gems, jewelry, gifts and hobby supplies.   Various craftsmen will be on hand to demonstrate skills like gem carving, wire wrapping, faceting, cabachon-making, polymer clay art, fetish carving and jewelry repair.

26
Dealers
This year will mark the 48th aniversary of this popular event.   The show will feature 26 dealers, and a variety of games for kids of all ages.   Each hour a number of door prizes will be awarded, and snacks, drinks and lunch will be available from a professional caterer.
Demonstrations on : Glass Bead Making, Precious Metal clay, Gem Faceting.

FREE PARKING AND FREE ADMISSION!!!

Show hours are from 10am to 6pm Saturday, and 10am to 5pm, Sunday, at the Veterans Memorial Auditorium, Overland Avenue and Culver Boulevard.

The show is sponsored by the Culver City Rock and Mineral Club Inc., a non-profit organization sponsored by the Culver City Human Services Department.

For more information, please email our Show Chairpersons.

Bring the whole family!  Junior rockhounds will be given free gift specimens and should enjoy the live demonstrations planned on different aspects of our hobby.

Culver City Rock and Mineral Club (CCR&MC), Culver City/Los Angeles, CA

Our club, for over fifty years, has promoted education, knowledge and skills development in the earth sciences and lapidary arts.Our interests include mineralogy, cutting, polishing, casting, metalsmithing, and field collecting for rocks, minerals, and fossils. We are the only affiliated CFMS club with this wide range of activities, in the metropolitan Los Angeles, Culver City and Santa Monica areas.

The Club operates a fully equipped lapidary shop for use by members, publishes a monthly bulletin called The Nugget, and organizes field trips to local collecting areas.   CCRMC sponsors the popular Fiesta of Gems, Rock and Mineral Show each summer. The Club maintains an extensive library of books and videotapes for loan – free of charge to its members.

Membership ranges between 120 to 150 people, teachers, engineers, photographers, IT professionals, jewelry makers etc. Some members are crazy about rocks, other love to make jewelry. We all enjoy a good time at our friendly parties, meetings, picnics and other activities
MEMBERS (and prospective members) ALERT ! If you have not renewed your membership: {click here to DOWNLOAD Application Form} Fill it up and mail it !