Non-fossil Amethyst Crystal Point
Crystalline Quartz (SiO2) with iron impurities • None (Geological Mineral Specimen)
Geological Period
Not applicable (Mineral formation timeframe varies widely)
Estimated Age
50 to 150 million years (Typical for common amethyst deposits)
Preservation Type
Crystallization (Geological process, not biological preservation)
Condition Assessment
Good/Fair (Shows significant surface weathering and point abrasion typical of raw tumbled or river-worn stones)
Taxonomic Classification
Non-biological; Mineral Class: Silicates; Species: Quartz (var. Amethyst)
Morphological Description
Elongated crystalline structure showing hexagonal symmetry with a pyramidal termination; translucent to transparent purple hue; exhibits conchoidal fracture patterns
Rock Matrix
Associated with volcanic basalt or hydrothermal veins; background surface in image appears to be polished Carrara-style marble
Formation & Location
Commonly found in geodes within volcanic rock; major deposits in Rio Grande do Sul (Brazil) and Artigas (Uruguay)
Size & Dimensions
Approximately 3-5 cm in length based on typical hand-sized mineral specimens
Value & Rarity
Estimated Market Value
$2 - $10 USD
Auction Estimate
$5 - $15 USD (Usually sold in wholesale lots rather than individual auction lots)
Rarity Assessment
Common (Amethyst is one of the most abundant semiprecious gemstones globally)
Scientific Significance
Provides evidence of hydrothermal activity and mineral precipitation in ancient volcanic cavities; useful for studying crystal growth kinetics
Preparation Recommendations
Clean with mild detergent and distilled water; avoid prolonged exposure to direct UV sunlight which can fade the purple color
Notable Features
Exhibits distinct color zoning typical of natural amethyst where iron concentration varies during crystal formation