Epidote
Epidote · Mineral Specimen
Crystal System
Monoclinic; typically prismatic crystals heavily striated parallel to the elongation axis, or massive and granular aggregates.
Mineral Group
Silicates (Sorosilicates)
Chemical Formula
Ca2Al2(Fe3+,Al)(SiO4)(Si2O7)O(OH)
Formation Process
Hydrothermal alteration and low-grade regional metamorphism (greenschist facies) of igneous and sedimentary rocks containing calcium and iron.
About This Crystal
Exhibits a matrix of dark green to near-black prismatic crystals showing strong striations, intergrown with brighter yellowish-green micro-crystals and crystalline aggregates. Luster is vitreous to resinous, and transparency ranges from translucent to opaque.
Physical Characteristics
Color ranges from pistachio-green, yellowish-green to dark green and black. Streak is gray-white. Perfect cleavage in one direction. Fracture is uneven to splintery. Specific gravity is approximately 3.3 to 3.5. Brittle tenacity.
Optical Properties
Biaxial negative with strong pleochroism showing shades of green, brown, and yellow. High birefringence.
Hardness & Durability
Origin Region
Notable sources include Pakistan, Austria, Norway, and the USA (Alaska). Forms in metamorphic and hydrothermal environments.
Hardness & Durability
Mohs hardness of 6 to 7. Moderate durability; perfect cleavage means it can split under sharp impacts, making it less suitable for everyday rings.
Care & Maintenance
Clean with warm soapy water and a soft brush. Avoid ultrasonic cleaners, harsh chemicals, and sudden thermal shock.
Rarity & Value
Common to uncommon depending on crystal quality and perfection. Fine crystal clusters on matrix are sought after by mineral collectors.
Special Characteristics
Strong pleochroism and distinct prismatic striations along with characteristic pistachio-green to dark green coloration.
Lore & History
Named from the Greek word for 'increase' due to the base of its crystal prism having one side longer than the other. In metaphysical practices, it is often considered a stone of attraction and manifestation, traditionally associated with the heart chakra.