Amethyst Geodes from Sonora, Mexico feature small double terminated amethyst crystals and druzy inside a pale pink and white matrix. These are already open geodes with sizes ranging from 4 cm - 10 cm (1.5" - 4") in diameter. Its chemical formula is SiO₂ and owes its purple coloration to irradiation of ferrous iron: Fe³⁺.

35 geode/pieces in flat.