Brazilianite's lovely green to yellow colors make it a must for gem collectors. Large faceted stones are often flawed, but smaller cut gems can make beautiful jewelry pieces.
The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.
|Crystallography||Monoclinic. Crystals equant, prismatic, spear-shaped; also striated.|
|Colors||Colorless, pale yellow, yellowish-green, greenish.|
|Cleavage||Good 1 direction.|
|Transparency||Translucent to transparent.|
|Pleochroism||Weak, merely a change in shade of color.|
|Optics||α = 1.602; β = 1.609; γ = 1.621-1.623. Biaxial (+), 2V = 71°|
|Etymology||After Brazil, where the gem was first discovered.|
|Occurrence||Hydrothermal mineral in pegmatitic cavities.|
Discovered in Brazil in 1944, large uncut brazilianite stones reside in many museums. Pieces such as these could yield large gems, but clean faceted gems over 15 carats are a great rarity. However, they make stunning crystal specimens.
Brazil, notably Conselheira Pena, Minas Gerais, remains the principal source of gem quality material in crystals up to large sizes. The Palermo Mine in Grafton, New Hampshire and sites in Yukon, Canada also yield fine but smaller specimens.
Crystals from Brazil range in size up to 12 x 8 cm. Although some large gems have been cut, most gems range from 1-10 carats, or even smaller. Cut stones over 5 carats are scarce today.
- American Museum of Natural History (New York): 23 (emerald cut, Brazil), 19 (round, yellow).
- Smithsonian Institution (Washington, D.C): 41.9 and 17.0 (yellow, Brazil).
- Private Collection: 24 (yellow, Brazil).
Heating brazilianite gems up to 140º C/284º F can lead to color loss. Heating up to 300º C/572º F will turn them colorless. A jeweler’s torch will easily reach these temperatures, so be wary if you’re taking a jewelry piece for repairs. Although brazilianites have a moderate hardness, their cleavage and fracture tendency make protective settings and occasional wear good ideas. Avoid mechanical cleaning such as steam or ultrasonic processes. Instead, use a soft brush, mild detergent, and warm water for cleaning. Consult our gemstone jewelry cleaning guide for more recommendations.