Amatista
Cuarzo is a mineral with formula SiO₂, in the Silicatos group. This specimen comes from Piedra Parada, Tatatilas, México and joined the Terrium collection in 2010.
Description
Two amethyst flowers perched on the crest of a whitish-grey matrix, itself covered by scattered much smaller quartz crystals. The lustrous crystals show a delicate blush-purple colour, deepest at the terminations, with stepped-growth prism faces. The terminations display the "purple blush" typical of Veracruz material.
About Cuarzo
Pieces on matrix are called "coronas", whereas loose or floater crystals are called "gallos". The belief that amethyst occurs in quartz veins is false; it in fact forms in vesicular andesite, within gas-formed cavities in the magma.
About the locality
Reaching the steep valleys of Piedra Parada requires a six-hour journey by mule or horse from the nearest village, an extreme challenge for extracting very fragile crystals. This remote Mexican locality is a major worldwide source, though its amethysts are often mislabelled as from Las Vigas, a municipality that functions only as a collection and commercial distribution point. To protect pieces during transport, boxes packed with sawdust are used, while the market follows strict full-lot sales that forbid selection of individual pieces. This system ensures that all extracted material is sold and supports the economy of the eighty mining families of Piedra Parada who depend on this resource of international standing.
Technical data
- Catalogue No.
- 0400
- Composition
- SiO₂
- Name
- Cuarzo
- Variety
- Amatista
- Group
- Silicatos
- Category
- Cresta Montis
- Mine
- Piedra Parada
- District / Municipality
- Tatatilas
- Country
- México
- Acquired
- 2010
- Ex-collection
- Diego Navarro
- Etymology
- From the German «Quarz», an old word of uncertain, probably Slavic, origin. “Amethyst” comes from the Greek «améthystos», “not drunken”.
- Quality
- Top
- Value trend
- Al alza