Cymophane

Irradiation of light variety produces dark (olive)-brown color: may be radioactive. - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 3 Cat's eye quartz, cat's eye tourmaline, bleached tiger's eye quartz, glass. - GIA 2019 In 1987 Japan's Kyocera Corporation created commercially-available synthetic cat's eye color-change alexandrite, which is a rare combination. - GIA 2019 8.5Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) 3.69 to 3.81Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) 1.739 to 1.770+Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) Biaxial/+,-Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) 0.007 to 0.013Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) Bluish (or yellowish according to other sources) chatoyancyGemdat.org, Management Team (2012) Yellow, greenHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) Transparent,TranslucentMichael O?Donoghue, Gems, Sixth Edition (2006) VitreousMichael O?Donoghue, Gems, Sixth Edition (2006) OrthorhombicHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) Microscopic tube-like cavities or needle-like inclusions of rutile in an orientation parallel to the c-axis - mindat.org Cymophane information at mindat.org Sri Lanka