Fire opal, Mexico

Colour zoning in ruby from Mong-Shu, Burma

Natural etching structure on a crystal face of diamond (trigons), polarised light

Inclusions of rutile (dark crystal and fine needles) and clusters of zircon grains in umbalite garnet, Tanzania

Inclusions of hematite in feldspar (sunstone), India

Dumortierite in rock crystal, Brazil, polarised light

Spinel crystal in dolomite marble, Burma

Fluid inclusions in quartz with bituminous daughter minerals, China

Inclusions of hematite in aquamarine, Tanzania