RockHoundBlog

Great Rockhound domains not being used, for sale.

Filed under: regular postings — Gary February 24, 2010 @ 9:21 am

In the world of domain names and rockhounding you can’t really match the two better.  This domain is perfect for our hobby/addiction and it’s a shame it’s not being used.  Anyways just letting everyone know that it’s out there for sale AND that the .ORG extension is perfect for it IMHO.

RockHounds.org

Also one other in the same same family-

RockHound.info

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Almandine – Mineral of the day

Filed under: Mineral of the day — Gary February 21, 2010 @ 1:55 pm

Almandine, also known incorrectly as almandite, is a species of mineral belonging to the 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. Almandine is an iron alumina garnet, of deep red color, inclining to purple. It is frequently cut with a convex face, or en cabochon, and is then known as carbuncle. Viewed through the spectroscope in a strong light, it generally shows three characteristic absorption bands. Almandine is one end-member of a mineral solid solution series, with the other end member being the garnet pyrope. The almandine crystal formula is: Fe3Al2(SiO4)3. Magnesium substitutes for the iron with increasingly pyrope-rich composition.

almandine

almandine

Almandine occurs rather abundantly in the gem-gravels of Sri Lanka, whence it has sometimes been called Ceylon-ruby. When the color inclines to a violet tint, the stone is often called Syrian garnet, a name said to be taken from Syriam, an ancient town of Pegu. Large deposits of fine almandine-garnets were found, some years ago, in the Northern Territory of Australia, and were at first taken for rubies and thus they were known in trade for some time afterwards as Australian rubies.

Almandine

Almandine is widely distributed. Fine rhombic dodecahedra occur in the schistose rocks of the Zillertal, in Tyrol, and are sometimes cut and polished. An almandine in which the ferrous oxide is replaced partly by magnesia is found at Luisenfeld in German East Africa. In the United States there are many localities which yield almandine. Fine crystals of almandine embedded in mica-schist occur near Fort Wrangell in Alaska. The coarse varieties of almandine are often crushed for use as an abrasive agent.

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Strunz Classification of Minerals

Filed under: regular postings — Gary @ 1:50 pm

Strunz classification is a scheme for categorizing minerals based upon their chemical composition, introduced by German mineralogist Karl Hugo Strunz (1910-2006) in his 1941 Mineralogische Tabellen.

Karl Hugo Strunz

Karl Hugo Strunz

As curator of the Mineralogical Museum of Friedrich-Wilhelms-Universität (now known as the Humboldt University of Berlin), Strunz had been tasked with sorting the museum’s geological collection according to crystal-chemical properties. His Mineralogical Tables, first published in 1941, has been through a number of modifications; the most recent edition, published in 2001, is the ninth.

The current scheme divides minerals into nine classes, which are further divided into divisions, families and groups according to chemical composition and crystal structure.

1. elements
2. sulfides and sulfosalts
3. halides
4. oxides and hydroxides
5. carbonates, nitrates and borates
6. sulfates, chromates, molybdates and tungstates
7. phosphates, arsenates and vanadates
8. silicates
9. organic compounds

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