28
Jan
ZIRCON
MINERAL: Zircon
CHEMISTRY: ZrSiO4
COLOR: Blue, red, yellow, orange, brown, green
REFRACTIVE INDEX:
HIGH: 1.925 to 1.984 (+/- 0.04...
26
Jan
TOURMALINE
MINERAL:Tourmaline
CHEMISTRY: Â Elbaite Na(Li1.5,Al1.5)Al6Si6O18(BO3)3(OH)4 Dravite NaMg3Al6Si6O18(BO3)3(OH)4 Liddicoatite Ca(Li2Al)A...
28
Jan
TANZANITE
MINERAL: ZOISITE
CHEMISTRY: Ca2Al3(SiO4)3(OH)
COLOR: Violet blue to bluish violet to violet purple
REFRACTIVE INDEX: 1.691 to 1.70...
26
Jan
SPINEL
MINERAL: spinel
CHEMISTRY: MgAl2O4
COLOR: red, orange, pink, purple, blue, black
REFRACTIVE INDEX: 1.718
BIREFRINGENCE: None
SPE...
26
Jan
SAPPHIRE
MINERAL: Corundum
CHEMISTRY: Al2O3
COLOR: Every color but red
REFRACTIVE INDEX: 1.762 to 1.770
BIREFRINGENCE: 0.008 to 0.010
SPE...
26
Jan
Ruby
MINERAL:Corundum
CHEMICAL COMPOSITION:Al2O3
COLOR: Red
REFRACTIVE INDEX: 1.762 to 1.770
BIREFRINGENCE: 0.008 to 0.010
SPECIFIC G...
28
Jan
PERIDOT
MINERAL: Olivine
CHEMISTRY: (MgFe)2SiO4
COLOR: Yellowish green
REFRACTIVE INDEX: 1.65 to 1.69
BIREFRINGENCE: 0.035 to 0.038
SPEC...
28
Jan
SUNSTONE
MINERAL: Feldspar
CHEMISTRY:
Orthoclase - KAlSi3O8
Oligoclase and labradorite - solid solution between NaAlSi3O8 and CaAl2Si2O8
C...
26
Jan
MORGANITE
MINERAL: Beryl
CHEMISTRY: Â Be3Al2Si6O18
COLOR: Pink to orange-pink
REFRACTIVE INDEX: 1.583 to 1.590
BIREFRINGENCE: Â 0.007 to 0.00...