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 containing mica and quartz, in aquamarine from Pakistan

Agate from Reichweiler, Germany

Partially etched diamond crystal

Two-phase inclusions in sapphire, Sri Lanka

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

Stress fissure («sun spangle») in baltic amber

Fire opal, Mexico