Agate is a banded chalcedony variety of quartz identified by concentric or parallel growth bands and waxy lustre.

Allanite is a rare-earth-bearing member of the epidote group with limited use as a gemstone and strong collector value.

Andradite is a calcium-iron garnet species that includes demantoid and melanite varieties.

Astro stone is a trade descriptor for decorative composite material rather than a recognized mineral species.

Astrophyllite is a rare complex silicate mineral seen as bronze radiating blades in matrix material.

Black jade is a trade color category for dark jade materials, most often nephrite in commercial use.

A dark body tone turns black opal into a stage for moving colour. Against that deeper background, flashes of red, green, blue, and orange can appear sharper and more dramatic than they do in lighter opal varieties.

Black Spinel sits among the more resilient gem materials used for jewellery, which shapes both how it wears and how it is collected. That combination of black body colour, 9 Mohs hardness, and vitreous lustre is what usually makes it recognisable in practice.

Black Tourmaline is often discussed with one eye on colour and the other on where the material comes from. That combination of black body colour, 7 Mohs hardness, and vitreous lustre is what usually makes it recognisable in practice.

Bumblebee jasper is a trade name for a patterned volcanic-sedimentary composite material, not a true quartz jasper.

Chrysanthemum stone is a patterned ornamental rock with white radiating mineral growths in dark matrix.

Galaxy stone is typically a decorative trade product rather than a mineral species designation.

Harlequin opal is a trade pattern descriptor for precious opal with geometric, patchy color play.

Hematite is an iron oxide mineral identified in gem use by metallic lustre and red-brown streak.

Kambaba jasper is a trade-name ornamental rock with green-black orbicular patterns, not a strict jasper species term.

Lava stone is a porous volcanic basalt used as an ornamental bead and decorative material.

Mahogany obsidian is an obsidian variety showing reddish-brown mottling from iron-rich inclusions.

Melanite is a black titanium-rich variety of andradite garnet.

Meteorite stone is a trade category for extraterrestrial material used in jewelry and collector pieces.

Mettle stone is handled as a trade-name decorative material requiring supplier-level composition disclosure.

Nigrine is an ambiguous term in gem trade usage and should be tied to tested mineral identity before strict species claims.

Obsidian is a natural volcanic glass formed by rapid cooling of silica-rich lava.

Onyx is a parallel-banded chalcedony variety of quartz, traditionally black and white in layered form.

Pearl is an organic gem formed by mollusks, represented in trade by both natural and cultured products.

Petrified wood is fossil wood in which original organic tissue has been replaced by silica minerals.

Picasso jasper is a trade-name patterned decorative rock used for graphic line-based lapidary designs.

Picture jasper is a patterned jasper variety known for natural landscape-like designs.

Sardonyx is a banded chalcedony combining sard-colored and onyx-style layers.

Schorl is the black iron-rich tourmaline species widely used in mineral and decorative markets.

Snowflake obsidian is a patterned obsidian variety containing cristobalite spherulites.

Tahitian pearl is a premium dark saltwater cultured pearl category.

Tektite is natural impact glass formed by meteorite impact events.

Tiger iron is a layered ornamental rock combining tiger eye, jasper, and hematite components.

Zebra jasper is a patterned ornamental stone category defined by high-contrast striping.