Inclusions of fossil plant debris in opal from Wollo, Ethiopia

Partially etched diamond crystal

Fluid inclusions containing mica and quartz, in aquamarine from Pakistan

Spinel crystal in dolomite marble, 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

Fluid inclusions in quartz with bituminous daughter minerals, China

Stress fissure («sun spangle») in baltic amber

Two-phase inclusions in tourmaline from Namibia