Bixbite profile is under factual gemological review. Properties shown here are provisional unless marked as verified.

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.

Bloodstone (heliotrope) is dark green chalcedony/jasper marked by red iron-oxide spots.

Blue apatite is a blue-colored member of the apatite group used as a collector and jewellery gemstone.

Blue chalcedony is a blue microcrystalline quartz variety valued for soft, uniform translucent colour.

Blue coral is generally a trade product category and often involves dyed or treated coral material.

Blue goldstone is a man-made glitter glass used as an ornamental jewellery material.

Blue lace agate is a pale blue banded chalcedony variety with fine lace-like white patterns.

Blue moonstone is a trade term for moonstone-type feldspar showing a blue sheen effect.

Blue quartz is a trade variety of quartz with blue appearance caused by inclusions or structural scattering.

Blue 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 blue body colour, 9 Mohs hardness, and vitreous lustre is what usually makes it recognisable in practice.

Blue Topaz profile is under factual gemological review. Properties shown here are provisional unless marked as verified.

Botswana agate is a finely banded agate variety known for subtle grey-brown and pinkish tones.

Boulder Opal earns attention when light begins to travel across or through it. That combination of multicolour body colour, opalescence, play of colour, iridescence optical effects, and 5.5 Mohs hardness is what usually makes it recognisable in practice. The effect is best judged in motion, since a static view rarely shows the full character of the stone.

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

Cactus quartz is a trade name for spirit-like quartz clusters where small crystals cover a larger central crystal.

Carnelian is an orange to red chalcedony variety of quartz, typically translucent with a waxy to vitreous surface lustre.

Cat's-eye apatite is a chatoyant apatite variety cut as cabochon to display a moving light band.

Cat's-eye chrysoberyl is chrysoberyl displaying a strong chatoyant eye caused by aligned inclusions.

Cat's-eye moonstone is moonstone-type feldspar showing a chatoyant band in suitable cabochon orientation.

Cat's-eye quartz is quartz showing a chatoyant eye caused by aligned fibrous or needle inclusions.