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Topaz with lepidolite
Chip Clark
Specimen | Catalog Number | Locality | Weight |
---|---|---|---|
Topaz | NMNH 142207 | Brazil, Minas Gerais |
Topaz is renowned for its ability to grow huge gem-quality crystals. It is an aluminum silicate mineral, and its crystal habit is typically prismatic with pyramidal terminations. Pure topaz is colorless, however impurities can impart many colors. The highly prized imperial topaz is an intense golden to reddish-orange color. More commonly topaz is colorless to pale blue or yellow.The color of most blue topaz is the result of irradiation and heat treatment; however, this topaz is natural color. It is from Minas Gerais, Brazil, and encrusted with the mineral lepidolite, a member of the mica family.