Quartz

Quartz (var. Amethyst) - [SiO₂] - “Spirit Quartz” / “Cactus Quartz” / "Pineapple Quartz" Small sample of pale lavender to violet, translucent quartz (var. amethyst; SiO₂) exhibiting characteristic spirit or cactus quartz growth. Numerous small, closely intergrown quartz crystals form a dense drusy coating, with a larger euhedral first-generation quartz crystal projecting above the aggregate. The larger crystal is prismatic with a well-developed rhombohedral termination and vitreous lustre. The surrounding second-generation crystals are predominantly euhedral and outward-projecting, producing the distinctive finely crystalline surface characteristic of spirit quartz. Colour ranges from nearly colourless and pale lavender to moderate violet. The crystals occur on a pale, quartz-rich matrix with minor yellow-brown colouration or staining.