Musgravite

{{Short description|Rare oxide mineral and gemstone}}

{{Infobox mineral

| name = Musgravite

| category = Oxide minerals

| image = File:Musgravit-G-EmpireTheWorldOfGems.jpg

| caption = Musgravite from Sri Lanka

| formula = (Mg,Fe,Zn)₂BeAl₆O₁₂

| strunz = 04.FC.25

| color = Grey green to green

| habit =

| system = Trigonal

| twinning =

| cleavage =

| fracture = Conchoidal

| mohs = 8–8.5

| luster = Vitreous

| refractive = n_ω = 1.739, n_ε = 1.735

| opticalprop = Uniaxial

| birefringence = δ = 0.014 to 0.016

| pleochroism =

| streak =

| gravity = 3.62–3.68

| melt =

| fusibility =

| diagnostic =

| solubility =

| diaphaneity = Transparent

| other =

| references =

}}

Musgravite or magnesiotaaffeite-6N’3S is a rare oxide mineral used as a gemstone. Its type locality is the Ernabella Mission, Musgrave Ranges, South Australia, for which it was named following its discovery in 1967. It is a member of the taaffeite family of minerals,[http://www.mindat.org/min-2816.html Magnesiotaaffeite-6N’3S on Mindat][http://www.gemdat.org/gem-27238.html Gemdat] and its chemical formula is Be(Mg, Fe, Zn)₂Al₆O₁₂. Its hardness is 8 to 8.5 on the Mohs scale. Due to its rarity, the mineral can sell for roughly USD$35,000 per carat.