Citrine

Routinely produced by heat-treatment of (smoky) amethyst: reddish tint, may show reddish-brown hematite inclusions (surrounded by crack). Non-dichroic unlike natural - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 7 7Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) 2.65Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) BrittleWalter Schumann, Gemstones of the world (2001) Very brittle NoneWalter Schumann, Gemstones of the world (2001) ConchoidalMichael O?Donoghue, Gems, Sixth Edition (2006) 1.544 to 1.553Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) Uniaxial/+Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) 0.009Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) Natural: weak; yellow - light yellow. Heat-treated: noneWalter Schumann, Gemstones of the world (2001) More from other references 0.013Walter Schumann, Gemstones of the world (2001) Star 6Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) Light yellow to dark yellow, gold-brownWalter Schumann, Gemstones of the world (2001) More from other references Yellow to orange, O2-→Fe3+ charge transfer, various Al3+ related color centers.W. William Hanneman, Pragmatic Spectroscopy For Gemologists (2011) Transparent,TranslucentUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) VitreousGemdat.org, Management Team (2012) NoneWalter Schumann, Gemstones of the world (2001) TrigonalUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) Hexagonal prisms with pyramidsWalter Schumann, Gemstones of the world (2001) More from other references Citrine information at mindat.org Bolivia  Laurs (2001, 2010) Brazil  Macri et al. (2006) Kievlenko E.Ya., Geology of gems, 2003, p. 113 Canada  Sinkankas (1997) Madagascar  Madagascar, extraLapis English No.1, 2001, p. 44 Pezzotta (2001) Danet (2009) Myanmar  Ted Themelis (2008) Gems & mines of Mogok Ted Themelis (2008) Gems & mines of Mogok Sri Lanka  Uruguay  Gilg et al. (2003)