mineral

Natural Gemstone Cabochons (Ruby, Moonstone, Emerald, Citrine)

Ruby (Al2O3:Cr), Moonstone (KAlSi3O8), Emerald (Be3Al2(SiO3)6:Cr), Citrine (SiO2)

AI-generated identification · may be incorrect

Varying hardness (7.5-9 on Mohs), Vitreous luster, high saturation colors, trigonal to orthorhombic crystal systems, density ranging from 2.6 to 4.0 g/cm3.

Identified January 22, 2026More mineral →

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Physical properties

Varying hardness (7.5-9 on Mohs), Vitreous luster, high saturation colors, trigonal to orthorhombic crystal systems, density ranging from 2.6 to 4.0 g/cm3.

Formation & geological history

Formed in metamorphic (Ruby/Emerald), igneous (Citrine), and pegmatitic (Moonstone) environments over millions of years.

Uses & applications

Primarily used in high-end jewelry, decorative arts, and as investment-grade specimens for collectors.

Geological facts

Rubies are actually red sapphires; both are the mineral corundum. Emeralds are the rarest of the four shown here, often containing distinct 'jardin' inclusions.

Field identification & locations

Identify by specific gravity, refractive index, and inclusion patterns. Common locations include Brazil, Myanmar, Sri Lanka, and Madagascar.

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Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Mineral Sand (Heavy Mineral Sand Concentrate)

Placer deposit concentrate containing minerals such as ilmenite, rutile, zircon, and magnetite

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Calcite–fluorite mineral specimen with iron-oxide staining

Calcite (CaCO₃), likely fluorite (CaF₂), with possible quartz and iron/manganese oxides

mineral

Septarian Pebble

Septarian nodule / Concretion

sedimentary

Soil with Mineral Detritus and Quartz Fragments

Regolith / Silicate Mineral Aggregate

sedimentary

Schist

Metamorphic