Aura Treated Agate Druzy / Geode Section
Microcrystalline and Macrocrystalline Quartz with Titanium/Gold Vacuum Deposition • Pseudo-fossil (Mineral Specimen); Geological mineral formation with thin-film vaporization coating
Geological Period
Geologically variable (typically Eocene to Miocene for similar Brazilian/Uruguayan agates)
Estimated Age
30 to 50 million years (mineral formation age, non-biological)
Preservation Type
Mineral crystallization (not organic preservation); anthropogenic surface alteration (Aura coating)
Condition Assessment
Fair to Good; the internal crystal structure is intact, but the specimen has been artificially altered which negates natural mineral value
Taxonomic Classification
Non-biological; Kingdom: Mineral; Class: Silicates; Species: Quartz (Agate var.)
Morphological Description
A cross-section of a chalcedony nodule showing a microcrystalline outer band and an inner cavity lined with small, terminating quartz crystals known as a 'druzy' surface. The surface exhibits a metallic, rainbow-like iridescence.
Rock Matrix
Igneous basalt or tuff (original host rock), primarily composed of chalcedony silica layers
Formation & Location
Commonly sourced from the Paraná Basin, Rio Grande do Sul (Brazil) or Artigas (Uruguay)
Size & Dimensions
Approximately 4-6 cm in diameter; typical for small decorative 'pocket' specimens
Value & Rarity
Estimated Market Value
$5.00 - $15.00 USD
Auction Estimate
$10.00 - $20.00 USD (in a decorative or metaphysical themed lot)
Rarity Assessment
Common; mass-produced for the gift shop and metaphysical markets through industrial chemical vapor deposition processes
Scientific Significance
Low; it is a common mineral specimen rather than a biological fossil. Its value is decorative/metaphysical rather than paleontological.
Preparation Recommendations
Keep away from harsh chemicals and direct sunlight to prevent fading of the thin-film coating; clean with a soft dry brush only
Notable Features
The most striking feature is the 'Aura' coating which provides an artificial dichroic effect, mimicking the natural play-of-color found in precious gems like opal.