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

Stress fissure («sun spangle») in baltic amber

Twin-crystal of chrysoberyl

Agate from Anzi, Maroc

Dendrites in agate

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

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

Inclusions of gilalite aggregates in rock crystal from Brazil

Fire opal, Mexico