Lemon Topas Ring / new- 5 g - (1)

Lemon Topaz Ring / new Set in 925 sterling silver Brand new and unworn Weight: 5.0 g / 25 ct 15.6 mm x 11.9 mm Ring size: U 59 UK R US 8.7 Fr 19 Inner diameter: 18.8 mm Brand new and unworn The mineral topaz, also known under the misleading trade names Finder’s Diamond, Killiecrankie Diamond, Mogok Diamond, Saxon Diamond and Slave Diamond[6], is a common island silicate with the chemical composition Al2[(F,OH)2|SiO4]. The fluorine (F) and hydroxide (OH) ions shown in parentheses can substitute for one another in the formula (substitution, diadochy), but always in the same proportion relative to the other constituents of the mineral. An F-free OH analogue is known as a synthetic compound.[7] Topaz crystallizes in the orthorhombic crystal system and typically forms well-developed and sometimes very planar crystals with short- to long-prismatic or columnar habit and a glassy luster on the surfaces. In pure form it is colorless and transparent. Due to multiple light refractions caused by lattice defects or polycrystalline development, it can also appear white and, due to trace impurities, take on yellow, pinkish, brownish-red, violet, light blue and pale green colors, with transparency accordingly decreasing. With a Mohs hardness of 8, topaz is among the hard minerals and serves as a reference on the Mohs scale, which goes up to 10 (diamond). Like diamond, it is also brittle and, after the (001) base plane, very easily cleaved with perfectly smooth fracture surfaces, which is often already suggested by cleavage cracks in the stone. Irregularly broken topazes show rough to weakly conchoidal fracture surfaces. Shipping as insured registered mail.

估價:$1.12

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