Yellow Quartz
Quartz var. Citrine · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal, typically forming prismatic crystals, masses, or as in this image, a small irregular or weathered pebble/fragment.
Mineral Group
Silicates (Subgroup: Tectosilicate)
Chemical Formula
SiO2
Formation Process
Forms primarily in igneous environments such as pegmatites, as well as hydrothermal veins and metamorphic rocks.
About This Crystal
A small, pale yellowish, semi-translucent fragment or pebble resting on a textured surface. The specimen exhibits a waxy to vitreous luster with an irregular shape, likely shaped by weathering or tumbling.
Physical Characteristics
Color ranges from pale yellow to brownish-yellow; white streak; conchoidal fracture with no distinct cleavage; specific gravity around 2.65; brittle tenacity.
Optical Properties
Uniaxial positive optical character, refractive index of 1.544 to 1.553, typically singly refractive in overall appearance with weak birefringence.
Hardness & Durability
Origin Region
Found globally; notable sources include Brazil, Madagascar, and the United States.
Hardness & Durability
Mohs hardness of 7, making it durable and suitable for general jewelry use with good toughness and stability against most chemicals.
Care & Maintenance
Clean with warm soapy water using a soft brush; avoid harsh ultrasonic cleaners or prolonged exposure to direct sunlight to prevent potential color fading.
Rarity & Value
Common; natural citrine is less common than heat-treated amethyst, with value depending on clarity, size, and depth of the yellow color.
Special Characteristics
May exhibit piezoelectric and pyroelectric properties under specific mechanical or thermal stress.
Lore & History
Historically associated with abundance, manifestation, and personal willpower, often referred to as the 'merchant's stone' in traditional crystal lore.