Agate from Reichweiler, Germany

«Red fox agate» from Patagonia, Argentina

Fire opal, Mexico

Structure in a healing fissure in topaz from Brazil

Colour zoning in ruby from Mong-Shu, Burma

Inclusions of rock crystal and rutile needles in quartz, Brazil, polarised light

Agate from Anzi, Maroc

Two-phase inclusion in amethyst, Brazil

Twin-crystal of chrysoberyl