Granite specimen
Graphic tourmaline, light micrograph
Luxulyanite, thin section, LM
Granite
Quartz vein in granite
Graphic granite rock
Devonian slates
Granite rock, light micrograph
Graphic granite rock, light micrograph
Quartz mineral stone, light micrograph
Tourmaline crystals in quartz
Hawk's Eye quartz stone
Schorl tourmaline crystal stone
Elbaite on albite and quartz
Schorl and quartz crystals in groundmass
Coastal rocks and pebbles
Ancient Roman columns
Titanite bearing granite
Rubellite tourmaline pendant
Tourmaline gemstones in quartz
Tourmaline specimen
Quartz and green tourmaline crystals
Tourmaline crystal specimen
Black tourmaline in mica schist
Tourmaline crystals in quartzite
Verdite green tourmaline gemstone
Rubellite Tourmaline in Lepidolite Mica
Green Tourmaline in Muscovite, Maine
Pink tourmaline crystals growing on mica
Crystals of green toumaline and pink lepidolite
Tourmaline pegmatite
Tourmaline Pegmatite
Bi-coloured tourmaline crystals
Tourmaline
Indicolite tourmaline faceted stone
Watermelon tourmaline crystalline stone
Tourmaline crystal specimens
Watermelon tourmaline
Elbaite mineral
Dravite mineral
Tourmaline embedded in feldspar rock
Elbaite mineral (tourmaline)
Mylonite, light micrograph
'Black' opal cabochon specimen
Opal specimen and cut stone
Molybdenite in granite
Molybdenite in granite groundmass
Granite, light micrograph
Zircon crystals on host rock
Tourmaline schorl specimen
Tourmaline gemstone
Tourmaline in quartz
Tourmaline quartz
Tourmaline gem, 365 carat
Tourmaline gem
Tourmaline mineral, light micrograph
Tourmaline mica in slate
Brixen granite
Brown granite stone
Variety of Igneous Rocks
Obsidian lava
Obsidian rock
Amethyst crystals
Boulder opal formation
Two-mica granite
Cut Watermelon Tourmaline gemstone
Yellow-green Tourmaline rough
Trillion cut tourmaline gemstone
Cut green Paraiba Tourmaline gemstone
Sample of granite
Microcline
Granodiorite, light micrograph
Granodiorite
Rubellite I
Rubellite II
Yellow Pollucite in coarse granite
Granite Tor on Bodmin Moor
Quartzite specimen
Opal gemstone
Peridotite, polarised light micrograph
Garnet
Diamond in kimberlite
Peridotite
Garnet in peridotite
Raw tourmaline crystal
Tourmaline gemstones and crystal
Tourmaline crystal, thin section
Black tourmaline, SEM
Tourmaline crystals in matrix
Schorl, the black variety of Tourmaline
Tourmaline Crystals, Minas Gerais, Brazil
Elbaite crystal, variety Tourmaline
Schorl variety of Tourmaline, Namibia
Tourmaline crystals
Albite with Tourmaline
Tourmaline crystals on Albite
Tourmaline crystal
Tourmaline in gneiss rock
Blue tourmaline crystals
Tourmaline gemstones
Granitic pegmatite
Tourmaline in pegmatite host rock
Opal specimen
Rough topaz
Quartz types
Opal gem necklace
Amazonite
Obsidian specimen
Diamond blade saw cutting through granite
Opalised fossil
Fuchsite mineral stone
Mineral properties, 18th century
Rhyolite mountain, Iceland
Muscovite and feldspar
Porphyritic microgranite
Petrified wood, fossil specimen
Citrine crystals
Forbach granite
Granite, polarised light micrograph
Tourmaline on quartz
Rough pinkish-red Rubellite
Jasper
Jasper breccia rock
Disintegrated Granite
Graphic Granite
White Granite
Opal gemstones
Blue opal gemstones
Opal specimens
Single piece of blue opal
Opal mineral stone
Opal rock
Black opal gemstone
Amethyst
Amethyst geode
Amethyst geodes
Garnet gemstone
Amethyst filled geode
Amethyst geode interior
Cursed amethyst
Amethyst and chalcedony
Allende meteorite specimen
Nephrite jade specimen
Tourmaline cross section
Cut green Tourmaline gemstone
Opal