SPINEL

Present Sources: Burma, Thailand, Sri Lanka, Cambodia, Laos and Vietnam.
Gemmological Characteristics
SPECIES: Spinel
TRANSPARENCY: transparent
COLOR: red, pink-red, pink, purple-red, violet- red, orange-brownish red
REFRACTIVE INDEX: 1.718
CRYSTAL SYSTEM: cubic
OPTIC CHARACTER: singly refractive
SPECIFIC GRAVITY: 3.60 MOHS
HARDNESS: 8
DISPERSION: .020
FLUORESCENCE: long wave-weak to strong red-orange, short wave-inert to weak red.
IDENTIFYING VISUAL CHARACTERISTICS: natural inclusions, e.g., needles, fingerprint inclusions of Spinel octahedral, etc.