Banding Onyx / Mexican Onyx
Calcite var. Banded Calcite (often commercially called Onyx or Alabaster) · Decorative Stone / Ornamental Mineral Specimen
Crystal System
Trigonal, massive to microcrystalline habit with distinct depositional banding layers
Mineral Group
Carbonates
Chemical Formula
CaCO3
Formation Process
Sedimentary or hydrothermal/chemical precipitation, typically formed in caves or hot spring environments through the deposition of calcium carbonate from mineral-rich waters.
About This Crystal
A polished slab displaying distinct parallel bands of alternating white, cream, grey, and rusty brown or amber tones. It has a smooth, polished surface with a waxy to vitreous luster and translucent to opaque light transmission.
Physical Characteristics
Color ranges from white and pale grey to tan and brown bands; white streak; perfect rhombohedral cleavage in pure crystals but massive in banded varieties; uneven to conchoidal fracture; specific gravity around 2.71; brittle tenacity.
Optical Properties
Uniaxial negative with strong birefringence, typically showing double refraction in transparent crystals, though this banded variety is generally translucent to opaque.
Hardness & Durability
Origin Region
Globally distributed; major commercial sources include Mexico, Pakistan, Egypt, and the USA. Typically forms in limestone caves, hot springs, and stalagmitic deposits.
Hardness & Durability
Mohs hardness of 3, making it relatively soft and easily scratched by a knife or copper coin. Low durability for heavy-wear jewelry, best suited for ornamental objects.
Care & Maintenance
Soft stone sensitive to acids like vinegar or citrus juice which etch the surface. Clean with a soft, damp cloth and mild soap. Avoid harsh chemical cleaners, prolonged water soaking, and ultrasonic cleaners.
Rarity & Value
Common and widely available; value is low to moderate, driven primarily by the size, craftsmanship, aesthetic appeal of the banding patterns, and polish of the carved object.
Special Characteristics
Striking parallel color banding created by varying mineral impurities during rhythmic depositional growth stages.
Lore & History
Historically carved by ancient civilizations including the Egyptians, Greeks, and Romans for vessels, amulets, and architectural elements. In modern metaphysical practices, it is associated with emotional balance, inner strength, and grounding energy.