Apatite

Description:

Vitreous luster; sensitive to acids. Deposits in Myanmar, Brazil, India, Kenya, Madagascar, Mexico, Norway, Sri Lanka, South Africa, and the United States. Apatite cat’s-eye is known.

Appearance:

• transparent to translucent
• yellow, green, violet, purple, blue, pink, brown, colorless
• phenomena: chatoyancy

Identification:

Refractive Index: 1.634-1.638 (+.012,-.006)
Absorption Spectra: 580 nm doublet common in yellow, colorless, and chatoyant stones
Cause of Color: blue – manganese; pink (fading) – color center; yellow, green – rare earth elements
Specific Gravity: 3.18 (1.05)
Hardness: 5 ; Toughness: fair

Stone Information from:

Gem Reference Guide, by GIA, ISBN 0-87311-019-6
Gemstones of the world, Third Edition, by Walter Schumann, ISBN 1-4027-4016-6
https://www.gemdat.org/gem-29229.html
https://www.mindat.org/min-29229.html