Polished Rock Crystal Pebble - Madagascar - Polished Minerals 5.1 cm / 61g / BK237

ROCK CRYSTAL belongs to the silicate group. It mainly contains silicon and oxygen. Its chemical formula is SiO2.

ROCK CRYSTAL occurs in cryptocrystalline form or with colorless prismatic crystals. Its hardness is equal to 7/10 on the Mohs scale and its density is 2.7 (1 for water). The line on the porcelain is white. Rock crystal, when pure, allows light to pass through perfectly.

The ghosts present in ROCK CRYSTALS are due to the formation of crystallization in successive stages.