Two-phase inclusions in sapphire, Sri Lanka

Inclusions of chrysotile fibres in demantoide garnet from Ural Mountains, Russia

Two-phase inclusion in amethyst, Brazil

Partially etched diamond crystal

Inclusions of fossil plant debris in opal from Wollo, Ethiopia

Colour zoning in ruby from Mong-Shu, Burma

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

Dumortierite in rock crystal, Brazil, polarised light

Inclusion of apatite in ruby from Tanzania