Quartz
Silicon dioxide (SiO2)
Mineral
Category
Sedimentary (Secondary Formation)
Browse sedimentary (secondary formation) specimens identified by the Rock Identifier community.
River Rock / Stream Pebble
Fluvial Clast / Rounded Sedimentary Particle
Sedimentary Rock (possibly composed of various minerals)
Red Jasper (beads)
Silicon Dioxide (SiO2) with iron inclusions
Sedimentary Rock
Chert (specifically Tan/Brown Chert)
Chert (SiO2)
sedimentary
Sandstone (Muddy/Silty Variety)
Arenite with high silt/clay content (clastic sedimentary rock)
sedimentary
Red Jasper
Jasper (Silicon Dioxide: SiO2 with Iron oxide inclusions)
sedimentary
Clear Quartz (beads in a bracelet)
Quartz (SiO2)
Mineral
Chert / Flint (a variety of Chert)
Chert (SiO2)
Sedimentary Rock (technically a microcrystalline quartz mineral aggregate)
Geode Nodules / Chalcedony Geode
Silicon Dioxide (SiO2) - Amorphous to Cryptocrystalline Quartz
sedimentary
Shale or Slate with Quartz Veins
Shale (fine-grained clastic sedimentary rock) or Slate (low-grade metamorphic rock formed from shale) with Quartz (SiO2) veins
Metamorphic, likely Sedimentary with Quartz veins
Garnet (Red Garnet)
Garnet Group. The red varieties seen in jewelry are typically Almandine (Fe3Al2(SiO4)3), Pyrope (Mg3Al2(SiO4)3), or a mix of the two (pyrope-almandine series).
Mineral (specifically, a variety of the mineral species Pyrope-Almandine Garnet)
Pyrite
Iron Pyrite (FeS2)
mineral
Fluorite Bracelet (light green beads) and possibly Lavender Jadeite (purple bead)
Fluorite: CaF₂ (Calcium Fluoride); Jadeite: NaAlSi₂O₆ (Sodium Aluminum Silicate)
Mineral for Fluorite; Mineral/Rock for Jadeite (as it's often a rock composed primarily of jadeite mineral)
Garnet (likely Almandine or a blend)
Garnet group: X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+. Given the dark, somewhat reddish-brown appearance in the image, it's likely Almandine (Fe3Al2(SiO4)3) or a mix with other iron-rich garnets.
Mineral
Carnelian
Carnelian (a variety of Chalcedony, SiO2)
Mineral
Red Jasper
Silicon dioxide (SiO2) with iron oxide (Fe2O3) inclusions
sedimentary
Chert (specifically Jasper or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Hematite
Hematite (Fe2O3)
mineral
Quartz (likely a clear or rock crystal variety)
Quartz (SiO2 - Silicon Dioxide)
Mineral
Petoskey Stone
Hexagonaria percarinata (Fossilized Coral)
sedimentary
Quartz (Common Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Satin Spar Selenite
Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)
mineral
Botryoidal Hematite (Kidney Ore)
Hematite (Fe2O3)
Mineral
Amethyst
Quartz (SiO2) variety
Mineral
Calcite
Calcite (CaCO 3)
Mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Agate (various color varieties)
SiO₂ (Silicon Dioxide)
Mineral (specifically a variety of Chalcedony, which is a microcrystalline quartz)
Shale or Mudstone (Based on appearance)
Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)
Sedimentary
Quartz
Quartz (Silicon Dioxide, SiO2)
Mineral
Brick
Fired clay or Ceramic material (no specific mineralogical scientific name as it's a composite)
Man-made material (constructed)
Fossilized Gastropod (Snail)
Class Gastropoda (internal mold or 'steinkern')
sedimentary
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Leopard Skin Jasper
Chalcedony (cryptocrystalline Quartz)
Mineral
Mookaite Jasper
Siliceous sedimentary rock (variety of Jasper/Chert)
Sedimentary Rock
Orthoclase Feldspar (or K-Feldspar)
Orthoclase (KAlSi3O8)
Mineral
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide, SiO2)
mineral
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2 (Silicon Dioxide)
Mineral
Calcite (likely a tumbled specimen)
Calcite (CaCO 3 )
Mineral
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral
Opal
Hydrous silicon dioxide (SiO2·nH2O)
mineral
Mookaite Jasper
Siliceous (chert) sedimentary rock, a form of Jasper
Sedimentary