Stress fissure («sun spangle») in baltic amber

Agate from Reichweiler, Germany

Inclusions of hematite in feldspar (sunstone), India

Spinel crystal in dolomite marble, Burma

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

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

Fire opal, Mexico

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

Inclusions of fossil plant debris in opal from Wollo, Ethiopia