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

Inclusion of apatite in ruby from Tanzania

Natural etching structure on a crystal face of diamond (trigons), polarised light

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

Structure in a healing fissure in topaz from Brazil

«Red fox agate» from Patagonia, Argentina

Inclusions of fossil plant debris in opal from Wollo, Ethiopia

Dendrites in agate

Two-phase inclusions in sapphire, Sri Lanka