Pumice
Pumice (volcanic glass froth)
Category
Browse man made glass (not a natural rock or mineral) specimens identified by the Rock Identifier community.
Pumice
Pumice (volcanic glass froth)
Gold Nugget
Native Gold (Au)
Diamond (or Cubic Zirconia)
Crystallized Carbon (C) for Diamond; Zirconium Dioxide (ZrO2) for CZ
Chert (specifically Gray Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Blue Agate (likely Dyed)
Silicon Dioxide (SiO2) - Chalcedony variety
Basalt
Basalt (composition: Plagioclase, Pyroxene, and Olivine)
Smoky Quartz
Silicon Dioxide (SiO2)
Graphite
Graphite (Native Carbon, C)
Snowflake Obsidian
Volcanic glass (SiO2) with Cristobalite (SiO2) inclusions
Rock Crystal Quartz
Quartz (SiO₂)
Quartzite (River Pebble)
Meta-quartzite (composed primarily of SiO2)
Granitic Pegmatite
Coarse-grained Granite (KAlSi3O8 + SiO2)
Green Fluorite (Beaded)
Fluorite (Calcium Fluoride, CaF2)
Pink Dyed Agate (Banded Chalcedony)
Silicon dioxide (SiO2) - variety Chalcedony
Banded Chert in Matrix
Microcrystalline Quartz (SiO2)
Sandstone with Magnetite and Iron Staining
Clastic Sedimentary Rock (contains Fe3O4 and Limonite/Hematite)
Chert (with Quartz vein)
Chert (Silicon Dioxide, SiO2)
Agate (specifically a Yellow/Honey Agate)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Yellow Quartzite (River Pebble)
Quartzite (SiO2)
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Diamond
Diamond (pure carbon, C)
Smoky Quartz (Herkimer-style)
Silicon Dioxide (SiO2)
Fluorite (Green Fluorite on Host Rock)
Fluorite (Calcium Fluoride, CaF2)
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
Quartzite
Quartzite (SiO2)
Chert (Honey Chert or Chalcedony Pebble)
Cryptocrystalline Quartz (SiO2)
Red Sandstone
Arenite (predominantly SiO2 with Fe2O3)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Chert / Flint Conglomerate
Silicified Sedimentary Breccia (primarily SiO2)
Quartzite
Quartzite (primarily SiO2)
Quartzite Pebbler
Quartzite (SiO2)
Unakite
Epidotized Granite
Peridot (likely, given the color and bead form)
Olivine, variety Peridot (Mg,Fe)2SiO4
Granite Pebble (Salt and Pepper Granite)
Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Biotite/Amphibole)
Turquoise (likely stabilized or Howlite/Magnesite imitation)
Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
Chert (Nodular Chert)
Microcrystalline Silica (SiO2)
Unakite
Epidotized Granite
Chert / Flint
Chert (Cryptocrystalline Silica, SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2) with iron oxide impurities
Chert Breccia
Brecciated Microcrystalline Quartz (SiO2)
Chert (Field Stone/Pebble)
Microcrystalline or cryptocrystalline Quartz (SiO2)