Tephroite Value, Price, and Jewelry Information
Tephroite is generally reddish brown and barely translucent. However, it takes a good polish and is massive enough to make good cabochons. Only the New Jersey and Australian localities seem to have provided such material, however. Faceted gems are unknown.
Streak: pale gray.
Optics:a =1.770-1.788; β= 1.807-1.810; γ=1.817-1.825.
Biaxial (—).
Occurrence: In iron-manganese ore deposits and associated skarns.
California; Colorado.
Franklin and Sterling Hill, New Jersey: cuttable.
England; Sweden; France; Japan.
Tamworth. NS.W. Australia: small Mn deposits with massive tephroite streaks in rhodonite.
This material is suitable for cabochons.
Comments: Tephroite is generally reddish brown and barely translucent. However, it takes a good polish and is massive enough to make good cabochons. Only the New Jersey and Australian localities seem to have provided such material, however. Faceted gems are unknown.
Name: From the Greek tephros, meaning ash colored.
