Sterling silver pendant, Ag 925/1000. Rhodium plated. With genuine, natural gemstone - snowflake obsidian. Gemstone characteristics: Type: Natural gemstone obsidian. Country of origin: Argentine. Carat weight: 12.89 ct. Heart cut, smooth, dimensions 18x18 mm. Color: Black, with significant snow white snowflakes. Clarity: Opaque. Luster: Very good.Hardness: 5.0 - 5.5 Mohs. Specific gravity: 2.33 - 2.50. Refractive index: 1.450 - 1.550. Gemstone is formed by a natural volcanic glass with beautiful snow-white flakes of cristobalite, incurred by partial crystallization of volcanic glass. Loop is movable - inner diameter ca. 6x4 mm.