chrysoberyl

{{Infobox mineral |boxbgcolor=#d9d87e| name = Chrysoberyl | category = Oxide minerals | boxwidth = | image = Chrysoberyl-282796.jpg | imagesize = 260px | alt = | caption = Cyclic trilling of chrysoberyl | formula = BeAl2O4 | IMAsymbol = Cbrl | strunz = 4.BA.05 | system = Orthorhombic | class = Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) | symmetry = Pbnm | unit cell = a = 5.481 Å, b = 9.415 Å, c = 4.428 Å; Z = 4 | color = Various shades of green, emerald-green yellow, blue, brownish to greenish black, may be raspberry-red under incandescent light when chromian; colorless, pale shades of yellow, green, or red in transmitted light | habit = Crystals tabular or short prismatic, prominently striated | twinning = Contact and penetration twins common, often repeated forming rosette structures | cleavage = Distinct on {110}, imperfect on {010}, poor on {001} | fracture = Conchoidal to uneven | tenacity = Brittle | mohs = 8.5 | luster = Vitreous | opticalprop = Biaxial (+) | refractive = nα=1.745 nβ=1.748 nγ=1.754 | pleochroism = X = red; Y = yellow-orange; Z = emerald-green | 2V = Measured: 70° | streak = White | gravity = 3.5–3.84 | melt = | fusibility = | solubility = | other = | references = | var1 = Alexandrite | var1text = Color change; green to red | var2 = Cymophane | var2text = Chatoyant }}

thumb|Main chrysoberyl producing countries