Green Banded Onyx / Mexican Onyx
Calcite var. Travertine (commonly sold commercially as 'Onyx') · Decorative Stone / Ornamental Mineral Specimen
Crystal System
Trigonal, massive or banded habit formed via chemical precipitation
Mineral Group
Carbonates
Chemical Formula
CaCO3
Formation Process
Sedimentary or hydrothermal chemical precipitation from calcium carbonate-rich water in caves or hot springs
About This Crystal
Hand-carved polished pyramid shape displaying distinct horizontal banding with translucent white, cream, and warm amber-brown layers. Luster is vitreous to waxy on the highly polished facets.
Physical Characteristics
White to light green body color with brown bands; white streak; no true cleavage (exhibits parting); conchoidal to uneven fracture; specific gravity around 2.71; reactive to acids with effervescence; often exhibits weak white or pink fluorescence under UV light
Optical Properties
Uniaxial negative with high birefringence, displaying strong double refraction when transparent; non-pleochroic
Hardness & Durability
Origin Region
Mexico, Pakistan, Egypt, and Iran; formed in limestone caves, hot springs, and speleothems
Hardness & Durability
Mohs hardness of 3; low durability, scratches easily with a knife or copper coin; vulnerable to acids and scratching, poor choice for daily-wear rings
Care & Maintenance
Clean with a soft, damp cloth; avoid all acidic substances like vinegar, lemon juice, or commercial chemical cleaners; store separately to prevent scratching by harder stones
Rarity & Value
Common; widely available globally as polished decorative items and carvings; inexpensive to moderately priced depending on size and craftsmanship
Special Characteristics
Striking parallel banding, translucency allowing light transmission through the pyramid structure, and natural color zoning created by mineral impurities during deposition
Lore & History
Historically used in ancient Egypt, Greece, and Rome for carving vessels, amulets, and decorative pillars. In modern metaphysical practices, it is often associated with the solar plexus and heart chakras, believed to promote emotional balance, inner strength, and self-control, though these are traditional beliefs without scientific backing