Diamond (Rough)
Diamond (C)
Mineral
Category
Man Made Byproduct (Often Mistaken For Obsidian Or Emerald)
Browse man made byproduct (often mistaken for obsidian or emerald) specimens identified by the Rock Identifier community.
Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Marble
Metamorphosed Limestone/Dolomite
metamorphic
Quartz (in matrix)
Quartz (SiO₂)
mineral
Slate
Slate (a fine-grained, foliated metamorphic rock). Mineral composition: Primarily composed of mica minerals (muscovite, chlorite, sericite) and quartz, with minor amounts of hematite, pyrite, and other accessory minerals.
sedimentary
Diamond
Diamond (carbon allotrope), C (chemical formula)
Mineral
Banded Gneiss
Gneiss (typically quartz, feldspar, mica, amphibole composition)
metamorphic
Unidentified Rock Fragment
Unknown
Rock
Dolomite
Dolomite (CaMg(CO3)2)
Mineral
Schist
Schist (various mineralogical compositions including mica, chlorite, talc, etc.)
Metamorphic
Chalcedony (Banded/Mottled Variety)
Chalcedony (a cryptocrystalline variety of Quartz, SiO2)
Mineral
Greywacke (likely)
Greywacke (a type of sandstone)
Sedimentary
Selenite
Gypsum (CaSO4·2H2O), specifically the crystalline variety Selenite
Mineral
Blue Chalcedony and Picture Jasper Beads
Blue Chalcedony (SiO2), Picture Jasper (SiO2)
Mineral
Banded Gneiss
Gneiss (pronounced 'nice')
metamorphic
Puddingstone
Conglomerate (specifically a type of jasper conglomerate or quartz conglomerate)
Sedimentary
Pyrite
Pyrite (Iron sulfide, FeS₂)
mineral
Sandstone
Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)
Sedimentary
Fluorite
Fluorite (Calcium Fluoride, CaF2)
Mineral
Clear Quartz (or Rock Crystal)
Quartz (SiO₂)
Mineral
Sandstone
Sandstone (Clastic Sedimentary Rock)
Sedimentary Rock
Diorite (possibly fine-grained variety or a related intermediate intrusive rock like a felsic gabbro or a dark granodiorite)
Diorite (Igneous rock, intrusive, intermediate composition)
Igneous Rock
Serpentinite
Serpentinite (a rock composed predominantly of serpentine group minerals)
metamorphic
Jade
Jadeite or Nephrite
Mineral/Mineraloid
Granite
Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)
igneous
Pebble (likely a type of sandstone or quartzite pebble)
Clastic Sediment (specifically, a rudite-sized clast). If the pebble is composed of a specific rock type, its scientific name would be that rock type (e.g., 'Quartzite pebble', 'Granite pebble', 'Chert pebble'). Given its appearance, it is likely a metamorphic quartzite pebble or a hard sandstone pebble.
Sedimentary rock
Sandstone
Sandstone (lithified arenite/wacke)
Sedimentary Rock
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral, often found as detrital grains in sedimentary rocks