Beryl
Description
Any of several minerals and gemstones composed of beryllium aluminum silicate. The best known beryls are Emerald (green) and Aquamarine (blue); other types are Heliodor (yellow) and Morganite (pink). Beryl crystals occur in granites and pegmatites. Gem quality beryl crystals are found worldwide. They have been gathered or mined since 3000 BCE. High quality beryl gems are mined in Columbia, Brazil, Zimbabwe, South Africa, Namibia, and the U.S. (Califonia, Maine, Connecticut, South Dakota, and North Carolina). The largest recorded beryl crystal was found in Madagascar; it weighed 36 tons and measured 60 feet long.
Synonyms and Related Terms
emerald (bright green); aquamarine (blue); heliodor (yellow to brown); morganite (pink to purple); goshenite (colorless); Beryll (Deut.); béryl (Fr.); beril (Fr.); berilo (Esp., Port.); beryl (Ned.)
Other Properties
Hexagonal system with prismatic crystals usually striated lengthwise. Cleavage is poor in one direction. Weakly pleochroic.
Fracture = uneven to conchoidal. Luster = vitreous. Streak = colorless.
Fluorescence = none to weak. Synthetic stones may appear opaque and dull red under long UV light.
| Composition | Be3Al2(SiO3)6 |
|---|---|
| Mohs Hardness | 7.5 - 8.0 |
| Density | 2.68-2.83 |
| Refractive Index | 1.57 - 1.60 |
Hazards and Safety
Beryllium is a known carcinogen.
Additional Information
Mineralogy Database: Beryl
Comparisons
Additional Images
Beryl
Sources Checked for Data in Record
- Sue Fuller, Rocks and Minerals, DK Publishing, Inc., New York City, 1995
- Jack Odgen, Jewellery of the Ancient World, Rizzoli International Publications Inc., New York City, 1982
- R.F.Symmes, T.T.Harding, Paul Taylor, Rocks, Fossils and Gems, DK Publishing, Inc., New York City, 1997
- A.Lucas, J.R.Harris, Ancient Egyptian Materials and Industries, Edward Arnold Publishers Ltd., London, 4th edition, 1962
- Encyclopedia Britannica, http://www.britannica.com Comment: "beryl" Encyclopædia Britannica [Accessed September 19, 2003].
- Website address 1 Comment: http://www.geo.utexas.edu/courses/347k/redesign/gem_notes/Beryl/beryl_triple_frame.htm (Fluorescence information)
- C.W.Chesterman, K.E.Lowe, Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf, New York, 1979
- Wikipedia, the free encyclopedia, at http://www.wikipedia.com Comment: http://en.wikipedia.org/wiki/Beryl (Accessed Oct. 18, 2005)
- G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 101
- Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
- Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997
- The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
- CRC Handbook of Chemistry and Physics, Robert Weast (ed.), CRC Press, Boca Raton, Florida, v. 61, 1980 Comment: density=2.69-2.7