Corundum Value, Price, and Jewelry Information
...Sapphire and ruby are prized jewelry stones. CORUNDUM: Sapphire, Sri Lanka (184, in gold pendant with diamonds). Photo © Joel E. Arem, PhD, FGA. Used with permission. Identifying...
Opal Value, Price, and Jewelry Information
...Opal, Australia (Stone in Bracelet ~ 20 carats). Photo © Joel E. Arem, PhD, FGA. Used with permission. Opal is an amorphous form of silica, chemically similar to quartz, but...
Epidote Value, Price, and Jewelry Information
...Fe, Al)3Si3O12(OH) Mukhinite: Ca2(Al2V)Si3O12(OH). Hancockite: (Pb, Ca, Sr)2(Al, Fe) 3Si3O12(OH). ZOISITE: Thulite, Norway (each specimen ~2 inches across). Photo © Joel E. Arem, PhD, FGA. Used with permission. Colors Clinozoisite...
Labradorite Value, Price, and Jewelry Information
...blue sheen and the indices are: a= 1.550-1.553; γ = 1.560-1.561; birefringence 0.008-0.010; S.G. 2.70. FELDSPAR: Labradorite, Chihuahua, Mexico (36.45, 34.0, 24.26). Photo © Joel E. Arem, PhD, FGA. Used...
Gemology Reference Books: Reviews
...is available through Amazon. Color Encyclopedia of Gemstones. Joel Arem, Ph.D., F.G.A. Springer, 2nd edition, 1987. 248 pp. If you like romantic stories highlighting the glamour of gems, this book...
Understanding Gem Synthetics, Treatments, And Imitations, Part 3: Synthetic Diamond
...is a chapter from Dr. Joel Arem’s forthcoming book, Gems and Jewelry, 3rd Edition. © Joel E. Arem 2011-2013. The International Gem Society (IGS) gratefully thanks Dr. Arem for his...
Understanding Gem Synthetics, Treatments, And Imitations, Part 2: Crystal Growth
...is a chapter from Dr. Joel Arem’s forthcoming book, Gems and Jewelry, 3rd Edition. © Joel E. Arem 2011-2013. The International Gem Society (IGS) gratefully thanks Dr. Arem for his...
Understanding Gem Synthetics, Treatments, And Imitations, Part 5: Identifying Gemstone Treatments
...© Joel E. Arem 2011-2013. The International Gem Society (IGS) gratefully thanks Dr. Arem for his contributions to the field of gemology and for allowing us to reproduce this chapter....
Understanding Gem Synthetics, Treatments, And Imitations, Part 1: An Introduction
...3rd Edition. © Joel E. Arem 2011-2013. The International Gem Society (IGS) gratefully thanks Dr. Arem for his contributions to the field of gemology and for allowing us to reproduce...
Optics in Gemology
...termed isotropic and is characterized by a single refractive index, abbreviated in Arem’s Color Encyclopedia of Gemstones as N. In all other crystals, those that are not isometric, light is...
