Musgravite

Musgravite
Chemical composition	Magnesium-beryllium-aluminium oxide Mg2BeAl6O12
Crystal system	Trigonal
Hardness	8
Optic nature	uniaxial -
Refractive index	1.721 - 1.728
Birefringence	± 0.004
Specific gravity	± 3.69
Pleochroism	faint
Fluorescence	LW: inert SW: inert

Musgravite is a polytype of taaffeite and is known amongst mineralogists as "magnesiotaaffeite-6N'3S".
The, gemological, name is derived from the Musgrave Ranges in central Australia.

Prior to 2002 this mineral was named "musgravite" by mineralogists aswell as gemologists. We gemologists still use the name "musgravite".

Sources

• Taaffeite and Musgravite article from the GAAJ
• Hudson D R, Wilson A F, Threadgold I M (1967) A new polytype of taaffeite — a rare beryllium mineral from the granulites of central Australia, Mineralogical Magazine, 36, 305-310