Synthetic (Man Made Glass)

Quartz with Iron Staining

Silicon Dioxide (SiO2) with Hematite inclusions

Weathered quartz-rich rock, possibly chert or quartzite fragment

Indeterminate; likely microcrystalline quartz (SiO₂), possibly with iron-oxide staining

Tumbled yellow quartz (likely citrine or iron-stained quartz)

Quartz, SiO₂; yellow color from trace iron or irradiation/heat-related coloration

Amethyst (Tumbled Quarz)

Silicon Dioxide (SiO2) with iron impurities

Quartz Mineral Specimens

Quartz (Silicon Dioxide, SiO2)

Tumbled blue chalcedony (likely blue quartz/chalcedony)

Cryptocrystalline silica, SiO₂; likely chalcedony, possibly dyed or surface-coated

Snowflake Obsidian

Volcanic Glass with Spherulitic Cristobalite (SiO2)

Quartz pebble

Quartz (Silicon dioxide, SiO2)

Chert or flint fragment

Microcrystalline quartz (SiO₂), likely silicified rock

Multi-Gemstone Quartz Bracelet (Amethyst, Aventurine, Rose Quartz, Clear Quartz)

Silicon Dioxide (SiO2) mixture

Quartz Grain

Silicon Dioxide (SiO2)

Quartz Vein in Host Rock (often Granite or Schist)

Silicon Dioxide (SiO2) within host matrix

Tumbled goldstone-like quartz pebble

Likely iron-stained quartz or jasper; exact identification requires testing

Tumbled cream chalcedony or quartz

Microcrystalline quartz, SiO₂; possibly iron-stained chalcedony

Quartz (Iron-stained River Pebble)

Silicon Dioxide (SiO2)

Quartz Pebble with Host Rock / Schist Matrix

Silicon Dioxide (SiO2) with Metamorphic Host Rock

Quartz with Iron Oxide Inclusions

Silicon Dioxide (SiO2)

Milky Quartz / Quartz Geode Fragment

Silicon Dioxide (SiO2)

Chert (Flint)

Microcrystalline Silica (SiO2)

Agate (Plume/Moss variety)

Cryptocrystalline Quartz (SiO2) with iron/manganese inclusions

Polished pink quartzite or jasper

Quartzite, predominantly SiO₂; possibly iron-stained jasper/chalcedony

Chert / Flint Nodule

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Tumbled milky quartz (likely chalcedony or quartzite)

Quartz/chalcedony, silicon dioxide (SiO₂)

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Rose Quartz

Silicon Dioxide (SiO2)

Pumice or Tufa/Travertine

Pumice (if igneous) or Calcareous Tufa (if sedimentary)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartz (Milky or Cloudy Quartz)

Quartz (Silicon Dioxide, SiO2)

Snowflake Obsidian

Volcanic Glass with Spherulite inclusions (mainly Cristobalite)

Clear Quartz

Silicon Dioxide (SiO2) / Rock Crystal

Milky Quartz Pebble

Crystalline Silicon Dioxide (SiO2)

Quartz-rich rock, possibly milky quartz or quartzite

Quartz (silicon dioxide, SiO₂); if granular and foliated, likely quartzite

Libyan Desert Glass

Natural Silica Glass (SiO2 with minor iron and titanium)

Sandstone (Quartz-rich Cobble)

Arenite

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silica - SiO2)

Quartz

Silicon dioxide (SiO2)

Small white mineral fragment

Indeterminate; possibly quartz, calcite, or feldspar

Chert (Flint)

Microcrystalline quartz (SiO2)

Chert

Microcrystalline quartz (SiO2)

Chert / Flint

Silicon dioxide (SiO2)

Iron-stained Quartz Pebble

Silicon Dioxide (SiO2) with Hematite/Limonite coatings