Yellow Calcite
Calcium Carbonate var. Yellow Calcite · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal crystal system; this specific specimen shows a massive, cleaved rhombohedral habit with grainy surface textures.
Mineral Group
Carbonate group; Specifically a Calcium Carbonate mineral.
Chemical Formula
CaCO3 (frequently contains trace inclusions of iron or organic matter contributing to the yellow hue)
Formation Process
Primarily sedimentary through chemical precipitation in marine environments or hydrothermal through hot springs and volcanic activity at low pressures.
About This Crystal
Translucent to semi-opaque pale yellow stone with a waxy to vitreous luster. Surface shows a grainy, saccharoidal (sugar-like) texture typical of crushed or cleaved calcite.
Physical Characteristics
Color: Pale yellow to honey. Streak: White. Cleavage: Perfect rhombohedral in three directions (not fully visible here due to rough surface). Specific Gravity: 2.71. Tenacity: Brittle. Fluorescence: Often shows weak red, blue, or yellow under UV light.
Optical Properties
Refractive Index: 1.486 - 1.658. Highly birefringent. Doubly refractive (often shows double vision when looking through clear pieces). No significant pleochroism.
Hardness & Durability
Origin Region
Commonly sourced from Mexico, Brazil, and the USA. Forms in sedimentary environments like limestone beds and hydrothermal veins.
Hardness & Durability
Mohs hardness of 3. Very soft and easily scratched by copper or steel. Brittle toughness; sensitive to sudden temperature changes and pressure.
Care & Maintenance
Clean only with warm soapy water. Never use ultrasonic or steam cleaners. Highly sensitive to acids (will effervesce and dissolve). Store separately to prevent scratches.
Rarity & Value
Common. Very affordable, typically sold by weight. Prices increase with higher transparency and deeper 'Orange' or 'Honey' saturation. Rarely treated.
Special Characteristics
Known for its 'acid test' reaction (fizzes with dilute HCl). Can show phantoms or zonations if sliced thin. Surface feels slightly soapy or waxy to the touch.
Lore & History
Historically used in limestone and marble construction. Metaphysically associated with the Solar Plexus chakra, believed to enhance self-confidence, memory, and mental clarity.