Euclase

Blue and green may be produced by irradiation of colorless stones - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 4 7.5Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references 3.08 to 3.12Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references BrittleWalter Schumann, Gemstones of the world (2001) PerfectHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) 1 perfect and easy cleavageMore from other references ConchoidalWalter Schumann, Gemstones of the world (2001) 1.650 to 1.677Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references Biaxial/+Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references 0.019 to 0.025Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references Weak: colorless-(greenish) - yellow-green - blue-greenHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) 0.016Arthur Thomas, Gemstones (2009) Colourless, greenish, bluish, greenish-blue, blueUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references Blue variety often shows redHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) Blue Fe2+-O-Fe3+ charge transfer. Green Cr3+ in octahedral coordinationW. William Hanneman, Pragmatic Spectroscopy For Gemologists (2011) TransparentUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references VitreousArthur Thomas, Gemstones (2009) Weak or noneWalter Schumann, Gemstones of the world (2001) MonoclinicHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references Flattened prismaticMichael O?Donoghue, Gems, Sixth Edition (2006) More from other references Euclase is found in pegmatites and is formed from the decomposition of beryl.Michael O?Donoghue, Gems, Sixth Edition (2006) Euclase information at mindat.org Brazil  Gems, Sixth Edition, Michael O’Donoghue, 2006, p. 410 Colombia  Emeralds of the World English extraLapis Vol. 2 2002 pp36-45 Fabre Minerals. Myanmar  Ted Themelis (2008) Gems & mines of Mogok Zimbabwe  Gems, Sixth Edition, Michael O’Donoghue, 2006, p. 410