Yellow Calcite
Calcite (Calcium Carbonate) · Mineral Specimen / Semi-Precious Decorative Stone
Crystal System
Trigonal; typically occurs in rhombohedral crystals, massive form, or coarse granular aggregates.
Mineral Group
Carbonates; Calcite group
Chemical Formula
CaCO3 (frequently with traces of Fe or Mg affecting color)
Formation Process
Sedimentary, metamorphic, and hydrothermal; often formed through chemical precipitation or in lime-rich metamorphic environments.
About This Crystal
The specimen exhibits a pale yellow, earthy to waxy appearance. It is translucent to opaque with a chunky, somewhat rhombohedral cleavage visible on the fractured surfaces.
Physical Characteristics
Color: Yellow to honey-yellow; Streak: White; Cleavage: Perfect rhombohedral in three directions; Fracture: Conchoidal to uneven; Specific Gravity: 2.71; Fluorescence: Often fluoresces pink or red under UV light.
Optical Properties
Uniaxial (-); Refractive Index: 1.486–1.658; very high birefringence which can lead to double refraction (strong doubling of images).
Hardness & Durability
Origin Region
Globally abundant; notable sources include Mexico, Brazil, USA, and Belgium.
Hardness & Durability
Mohs hardness: 3; very soft and brittle. Not recommended for high-wear jewelry; easily scratched by steel or copper.
Care & Maintenance
Avoid all acids (it will effervesce and dissolve); clean only with warm soapy water and a soft cloth. Keep away from harder stones to prevent scratching.
Rarity & Value
Common; low monetary value but highly valued as an educational or decorative mineral specimen due to its abundance.
Special Characteristics
Displays strong acid reaction (effervescence) with cold dilute HCl; notable for its perfect rhombohedral cleavage.
Lore & History
Historically used in various cultures as a lime source for mortars; in metaphysical lore, yellow calcite is often associated with the Solar Plexus chakra and believed to enhance motivation and energy.