Partially etched diamond crystal

Inclusion of apatite in ruby from Tanzania

Dumortierite in rock crystal, Brazil, polarised light

Inclusions of gilalite aggregates in rock crystal from Brazil

Stress fissure («sun spangle») in baltic amber

Two-phase inclusion in amethyst, Brazil

Two-phase inclusions in tourmaline from Namibia

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

Epigenetic inclusion (probanly melanterite) in quartz, Brazil, parallel polarisers