Basalt

Amygdaloidal Basalt

Amygdaloidal Basalt (extrusive volcanic rock with mineral inclusions)

Chalcedony (Common Opal variant)

Silicon dioxide (SiO2) with varying levels of hydration

Dark Igneous Rock (Likely Basalt or Diabase)

Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.

Scoria

Extrusive Basaltic Scoria

Scoria (Lava Rock)

Scoria (Basaltic Scoria)

Scoria (with likely iron oxidation)

Scoria (Basaltic Scoria)

Scoria (Vesicular Basalt)

Vesicular Basaltic Andesite

Basalt with Peridotite (Olivine) Xenolith

Olivine-rich Peridotite (Dunite) xenolith in Vesicular Basalt; chemical formula (Mg,Fe)2SiO4

Agate / Banded Chalcedony

Agate (Silicon Dioxide / SiO2)

Peridot

Olivine (Mg, Fe)2SiO4

Labradorite

(Ca, Na)(Al, Si)4O8 (Plagioclase Feldspar)

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Labradorite (Schiller Spar)

(Na,Ca)(Al,Si)4O8

Star Ruby

Corundum (Al2O3 with chromium and rutile inclusions)

Blue Sapphire (likely costume glass imitation)

Corundum (Al2O3) with iron/titanium impurities

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Ruby in Matrix

Corundum (Al2O3)

Labradorite

Labradorite ((Ca, Na)(Al, Si)4O8)

Vesicular Basalt (Iron-Stained)

Mafic Volcanic Rock (Basalt)

Basalt (Vesicular)

Extrusive Mafic Igneous Rock

Amethyst (Polished Point)

Crystalline Quartz (SiO2 with iron impurities)

Amygdaloidal Basalt

Amygdaloidal Basalt containing Zeolite and Calcite inclusions

Amygdaloidal Basalt

Amygdaloidal Basalt (extrusive volcanic rock)

Porphyritic Basalt

Porphyritic Basalt (Mafic extrusive rock)

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic volcanic rock)

Vesicular Basalt

Vesicular Basalt (rich in silicate minerals mostly Plagioclase and Pyroxene)

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic volcanic rock)

Vesicular Basalt

Amygdaloidal Basalt (Mafic extrusive volcanic rock)

Amygdaloidal Basalt

Amygdaloidal Basalt (containing secondary minerals like Quartz, Zeolites, or Calcite)

Prehnite on Basalt

Prehnite - Ca2Al(AlSi3O10)(OH)2

Olivine Basalt

Mafic Volcanic Rock (rich in (Mg, Fe)2SiO4)

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic volcanic rock)

Vesicular Basalt

Vesicular Basalt (Aphanitic Mafic Rock)

Basalt with Vesicles

Vesicular Basalt (comprising Plagioclase Feldspar, Pyroxene, and Olivine)

Vesicular Basalt

Extrusive Mafic Igneous Rock (Vesicular Basalt)

Celadonite in Amygdaloidal Basalt

K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2 (Celadonite mineral) within a Basalt matrix

Amethyst

Silicon Dioxide (SiO2) with trace Iron (Fe3+)

Olivine (Peridot)

Magnesium Iron Silicate ((Mg, Fe)2SiO4)

Chinese Writing Stone

Porphyritic Basalt or Porphyritic Andesite

Olivine

Magnesium Iron Silicate ((Mg, Fe)₂SiO₄)

Dyed Agate

Silicon Dioxide (SiO2) with artificial pigment

Peridotite (Dunite)

Peridotite (mostly Olivine: (Mg,Fe)2SiO4)