Dumortierite in rock crystal, Brazil, polarised light

Two-phase inclusions in tourmaline from Namibia

Inclusions of hematite in aquamarine, Tanzania

Fire opal, Mexico

Structure in a healing fissure in topaz from Brazil

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

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

Dendrites in agate

Inclusions of hematite in feldspar (sunstone), India