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

Inclusions of anatase crystal and rutile fibres in rock crystal from Brazil

Fluid inclusions containing mica and quartz, in aquamarine from Pakistan

Inclusions of hematite in feldspar (sunstone), India

Agate from Reichweiler, Germany

Midge included in amber from the Baltic coast, polarised light

Two-phase inclusion in amethyst, Brazil

Agate from Anzi, Maroc

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