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

Inclusion of apatite in ruby from Tanzania

Dendrites in agate

Two-phase inclusion in amethyst, Brazil

Inclusions of rock crystal and rutile needles in quartz, Brazil, polarised light

Stress fissure («sun spangle») in baltic amber

Agate from Anzi, Maroc

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

Two-phase inclusions in sapphire, Sri Lanka