Heliodor (Golden Beryl)

Color may be improved by heat-treatment or be created by irradiation of colorless variety - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 6 7.5 to 8Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) 2.68 to 2.72Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) BrittleWalter Schumann, Gemstones of the world (2001) IndistinctWalter Schumann, Gemstones of the world (2001) ConchoidalWalter Schumann, Gemstones of the world (2001) 1.566 to 1.579Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) Uniaxial/-Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) 0.005 to 0.009Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references Weak: golden-yellow, green-yellowWalter Schumann, Gemstones of the world (2001) 0.014Walter Schumann, Gemstones of the world (2001) YesUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) Lemon to golden yellowHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references The golden yellow color is attributed to Fe3+ ions.Color in the Beryl group. (2009) Transparent,Translucent,OpaqueWalter Schumann, Gemstones of the world (2001) HexagonalHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) Hexagonal prismsWalter Schumann, Gemstones of the world (2001) Planes of tiny 2 phase inclusions - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 6 Heliodor information at mindat.org Afghanistan  Glas (2002) Brazil  Menezes (2005) Cassedanne and Alves (1994) Cassedanne and Alves (1994) Kievlenko E.Ya., Geology of gems, 2003, p. 113 Cassedanne and Alves (1994) Madagascar  Pezzotta (2001) Laurs and Quinn (2002) Madagascar, extraLapis English No.1, 2001, p. 50 Namibia  Glas (2002), Laurs (2002) Jahn (2000), Jahn and Bahmann (2000), Glas (2002), Laurs (2002) Nigeria  J. Micheou (2009) Russia  Emlin (1996) Sri Lanka  Dissanayake et al. (2000) Ukraine  Koivula et al. (1993), Lyckberg (2005) USA  Jarnot (2005) Sinkankas (1997) Wise (2005) Wise (2005) Zimbabwe  Shmakin and Wedepohl (1999), Milisenda et al. (2000) Milisenda et al. (2000), Cairncross (2005), Wise (2005)