Inclusions of chrysotile fibres in demantoide garnet from Ural Mountains, Russia

Dendrites in agate

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

Spinel crystal in dolomite marble, Burma

Agate from Anzi, Maroc

Structure in a healing fissure in topaz from Brazil

Dumortierite in rock crystal, Brazil, polarised light

Colour zoning in ruby from Mong-Shu, Burma

Stress fissure («sun spangle») in baltic amber