8Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references
3.54 to 3.70Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references
IndistinctWalter Schumann, Gemstones of the world (2001) More from other references
ConchoidalArthur Thomas, Gemstones (2009)
1.710 to 1.735+Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references
IsotropicHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) Anomalous double refractionMore from other references
AbsentWalter Schumann, Gemstones of the world (2001)
0.020Arthur Thomas, Gemstones (2009)
Rare star 4/6Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references
Red, pink, orange, blue, violet, blue-greenUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references
Pink to red: inert to fluorescent red. Rare cobalt blue: reddish.Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
Violet to purple, Cr3+ in octahedral coordination and Fe2+ in tetrahedral coordination. Cobalt blue, Co2+ and Fe2+ in tetrahedral coordination. Bluish green Fe3+ and Fe2+ in tetrahedral coordination. Green (synthetic spinel), Cr3+ in octahedral coordination. Pink to red, Cr3+ in octahedral coordinationW. William Hanneman, Pragmatic Spectroscopy For Gemologists (2011)
TransparentUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references
VitreousArthur Thomas, Gemstones (2009)
Red spinel: strong - red; blue spinel: weak - reddish, green.Walter Schumann, Gemstones of the world (2001)
Pink to red: inert to reddish. Blue: inert. Rare cobalt blue: normally inert.Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references
Pink to red: inert to red-(orangy). Blue: greenish. Rare cobalt blue: weak to moderate red. Colorless and light green: inert to moderate orangy-red.Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references
There is a moderate glow of crimson colour for red and pink spinels. Some purple to mauve specimens glow plum-colour to lilac. Other specimens respond green.Michael O?Donoghue, Gems, Sixth Edition (2006)
IsometricHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references
Octahedra though some specimens may show dodecahedron or cube faces.Michael O?Donoghue, Gems, Sixth Edition (2006) More from other references
Spinel is formed at high temperatures as an accessory in igneous rocks, in regionally and contact metamorphosed limestones and in other contexts.Michael O?Donoghue, Gems, Sixth Edition (2006)
Spinel information at mindat.org
Afghanistan
Hughes (1994)
Cambodia
Hughes (1994)
China
Madagascar
[var: Pleonaste] Pezzotta (1999)
Milisenda et al. (2001)
Myanmar
Smith and Bosshart (2001)
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Hughes (1997)
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Pakistan
Hammer (2004)
Russia
Evseev (1994)
Sri Lanka
G. Zoysa (2009)
Dissanayake et al. (2000)
Dissanayake et al. (2000)
Dissanayake et al. (2000)
[var: Gahnospinel]
Milisenda and Henn (1999)
Tajikistan
Bowersox and Chamberlin (1995)
Tanzania
Hyrsl (2001)
Hyrsl (2001)
Hyrsl (2001)
Quinn and Laurs (2004)
Pardieu (2007)
Thailand
USA
Kunz, George Frederick (1883), American gems and precious stones: Mineral Resources U.S., 1882: 486; Kunz, George Frederick (1905a), Gems, jewelers’ materials, and ornamental stones of California: California Division Mines Bulletin 37, 171 pp.: 47; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 346.
Vietnam
Pardieu and Senoble (2005)
Pardieu and Senoble (2005)
Gemexplorer.org