Agate from Reichweiler, Germany

Agate from Anzi, Maroc

Inclusions of fossil plant debris in opal from Wollo, Ethiopia

Dumortierite in rock crystal, Brazil, polarised light

Stress fissure («sun spangle») in baltic amber

Spinel crystal in dolomite marble, Burma

Twin-crystal of chrysoberyl

Midge included in amber from the Baltic coast, polarised light

Structure in a healing fissure in topaz from Brazil