Prasiolite — Rolado

Prasiolite is a variety of quartz (SiO₂) whose light green to yellowish-green color results from the presence of traces of iron (Fe²⁺ and Fe³⁺) in specific defects in the crystalline lattice, subjected to natural thermal alteration processes or exposure to irradiation. It forms predominantly in granite pegmatites and hydrothermal veins, in the same environments as other varieties of quartz, occurring naturally in specific deposits where geochemical and irradiation conditions favor greenish pigmentation. The characteristic green hue is distinguished from other green varieties of quartz by the color originating from structural defects associated with iron, without the presence of external mineral inclusions. The mechanical rolling process progressively rounds the ends and corners of the pieces, resulting in a smoothed external profile that preserves the internal crystalline structure. Hardness: 7 on the Mohs scale. Density: 2.65 g/cm³. Crystalline system: trigonal. Available variations, approximate data: Size: 1 to 6 cm Unit weight: up to 0.090 kg (approx.) Average: 80 to 100 pieces per kg (approx.)