Agate from Anzi, Maroc

Dendrites in agate

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

Two-phase inclusions in sapphire, Sri Lanka

Spinel crystal in dolomite marble, Burma

Bubbles and swirls in moldavite (natural glass)

Fire opal, Mexico

Stress fissure («sun spangle») in baltic amber

Inclusions of anatase crystal and rutile fibres in rock crystal from Brazil