Inclusions of hematite in aquamarine, Tanzania

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

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

Inclusions of gilalite aggregates in rock crystal from Brazil

Twin-crystal of chrysoberyl

Bubbles and swirls in moldavite (natural glass)

Agate from Reichweiler, Germany

Two-Phase inclusions and rutile needles in rock crystal from Brazil

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