Green Tourmaline in Muscovite, Maine
Tourmaline pegmatite
Tourmaline Pegmatite
Pink tourmaline crystals growing on mica
Tourmaline
Rubellite Tourmaline in Lepidolite Mica
Verdite green tourmaline gemstone
Crystals of green toumaline and pink lepidolite
Bi-coloured tourmaline crystals
Tourmaline crystals in matrix
Tourmaline gemstone
Tourmaline Crystals, Minas Gerais, Brazil
Tourmaline gem
Tourmaline crystals
Tourmaline gem, 365 carat
Tourmaline mineral, light micrograph
Tourmaline mica in slate
Elbaite crystal, variety Tourmaline
Elbaite mineral (tourmaline)
Black tourmaline in mica schist
Graphic tourmaline, light micrograph
Tourmaline specimen
Watermelon tourmaline
Tourmaline crystal
Tourmaline gemstones
Tourmaline quartz
Aquamarine crystals
Granite specimen
Raw tourmaline crystal
Tourmaline gemstones and crystal
Tourmaline crystals in quartz
Tourmaline in quartz
Albite with Tourmaline
Tourmaline crystals on Albite
Tourmaline gemstones in quartz
Indicolite tourmaline faceted stone
Watermelon tourmaline crystalline stone
Schorl tourmaline crystal stone
Tourmaline in gneiss rock
Blue tourmaline crystals
Tourmaline crystals in quartzite
Rubellite I
Rubellite II
Schorl variety of Tourmaline, Namibia
Quartz and green tourmaline crystals
Schorl, the black variety of Tourmaline
Tourmaline embedded in feldspar rock
Schorl and quartz crystals in groundmass
Tourmaline crystal, thin section
Black tourmaline, SEM
Rubellite tourmaline pendant
Tourmaline crystal specimen
Tourmaline crystal specimens
Muscovite Mica
Aggregate of muscovite crystals
Hawk's Eye quartz stone
Elbaite mineral
Dravite mineral
Muscovite Mica, Ontario, Canada
Elbaite on albite and quartz
Granitic pegmatite
Fuchsite mineral stone
Two-mica granite
Yellow-green Tourmaline rough
Cut Watermelon Tourmaline gemstone
Trillion cut tourmaline gemstone
Mylonite, light micrograph
Cut green Paraiba Tourmaline gemstone
Mica schist folds, light micrograph
Tabular muscovite crystals and apatite
Opal gemstones
Blue opal gemstones
Single piece of blue opal
Opal mineral stone
Opal rock
Black opal gemstone
Aquamarine in muscovite matrix
Aquamarine in muscovite matrix, close
Sample of muscovite
Muscovite Star Mica
Muscovite mineral sample
Muscovite, light micrograph
Tourmaline in pegmatite host rock
Tourmaline schorl specimen
Muscovite crystals in rock groundmass
Emeralds
Muscovite
Opal specimen
Luxulyanite, thin section, LM
Opalised fossil
Orthogneiss, light micrograph
Polarized light experiments, 1847
Cut green Tourmaline gemstone
Tourmaline unworked stones
Obsidian mineral stone
Opal gemstone
Opal specimens
Tourmaline on quartz
Opal
Opal gem necklace
Opal in its host rock
Boulder opal formation
Opal gem and rock
Opal specimen and cut stone
Fire opal
Opal surface
Opal on bedrock
Ironstone matrix with potch opal
Potch opal with smooth and rough surface
Fire Opal
Aquamarine and muscovite
Tourmaline cross section
Round polished Common Opal
Polished specimen of muscovite
Amphibolite, light micrograph
Aquamarine on muscovite
Aquamarine in muscovite
Limburgite
Mineral properties, 18th century
'Black' opal cabochon specimen
Mineral samples
Garnet
Peridotite
Garnet in peridotite
Garnet in Schist
Turquoise stones
Cassiterite on muscovite groundmass
Rhyolitic geode
Obsidian, a glassy igneous rock
Obsidian
Variety of Igneous Rocks
Obsidian bubbles
Mahogany obsidian
Obsidian flow
Rhyolite mountain, Iceland
Quartz-feldspar porphyry
Obsidian-rich lava flow, Tenerife
Pebbles of snowflake obsidian rock lying on sand
Snowflake obsidian
Obsidian lava
Obsidian rock
Obsidian dome
Density of pumice and obsidian
Snowflake Obisidian