Spinel crystal in dolomite marble, Burma

Twin-crystal of chrysoberyl

Dendrites in agate

Agate from Reichweiler, Germany

Dumortierite in rock crystal, Brazil, polarised light

Two-phase inclusions in sapphire, Sri Lanka

Bubbles and swirls in moldavite (natural glass)

Structure in a healing fissure in topaz from Brazil

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