Chert (Arrowhead or Projectile Point)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Category
Browse mineraloid (organic) specimens identified by the Rock Identifier community.
Chert (Arrowhead or Projectile Point)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Amber
(C10H16O)n – an amorphous organic substance, primarily composed of polymerized isoprenoids.
Amber (Copal)
Organic gemstone, fossilized tree resin (often immature amber or copal)
Septarian Nodule (Septarian Dragon Stone)
Septarian Concretion (Composition: Calcite, Aragonite, and Limestone/Clay)
Petrified Wood
Silicified Wood (SiO2)
Red Jasper (beads)
SiO₂ (Silicon Dioxide)
Chert / Flint
Chert (varieties include Flint)
Shale
Shale
Chert / Flint
Chert (varietal name for microcrystalline quartz). Chemical formula: SiO₂
Pyrite
Pyrite (FeS2)
Shale or Mudstone (Based on appearance)
Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)
Red Jasper
Red Jasper (variety of Chalcedony, SiO₂)
Banded Chert
Chert (a microcrystalline variety of quartz, SiO2 with minor impurities)
Chert (varietal: Jasper or Flint likely, but definitive identification is difficult from image)
SiO₂ (silicon dioxide)
Pyrite
Pyrite (Iron Disulfide), FeS2
Brown Jasper (Likely)
Jasper (Cryptocrystalline Silicon Dioxide - SiO2)
Shale
Shale (clastic sedimentary rock)
Sea Glass (specifically Frosted White)
Amorphous Silica (substance: Sodium-calcium silicate glass)
Aventurine (likely Green Aventurine)
Silicon Dioxide (SiO2) with mineral inclusions
Green Sea Glass
Amorphous Silica (man-made glass), SiO2 + additive metal oxides
Sea Glass (Frosted Glass)
Amorphous Silica (SiO2) with various additives
Coal (specifically Bituminous or Anthracite)
Organic sedimentary rock; primarily Carbon (C) with varying H, S, O, N
Opalite (a synthetic glass, often confused with Opal)
Silicon dioxide glass (SiO2nH2O, for natural opal)
French Bulldog (Blue Variety)
Canis lupus familiaris
Cherry Creek Jasper (also known as Red Creek Jasper or Cherry Creek Agate)
Jasper, microcrystalline quartz (SiO₂)
Mookaite Jasper
Siliceous (chert) sedimentary rock, a form of Jasper
Shale or Argillite
Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)
Pyrite
Iron Pyrite (FeS2)
Coal (most likely Bituminous or Anthracite)
Bituminous Coal (Grade of Coal), Anthracite (Grade of Coal)
Mother of Pearl (Nacre)
Calcium Carbonate (primarily aragonite, with conchiolin)
Asphalt
Asphalt concrete (engineered material, not a naturally occurring rock/mineral in this form)
Petrified Wood
Silicified wood (Quartz/Chalcedony)
Conglomerate
Conglomerate
Petrified Wood
Silicified wood, primarily composed of Quartz (SiO2)
Chert (varietal known as Jasper or Flint)
Silicon Dioxide (SiO2)
Pyrite
Pyrite (Iron Disulfide), FeS2
Shale or Argillite
Shale (sedimentary) / Argillite (metamorphic)
Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)
Chert (microcrystalline quartz)
Sea Bean (Hamburger Bean)
Mucuna sloanei
Amber (Simulated/Faturan Style)
Resin mix (Likely Phenolic/Celluloid if synthetic, Succinite if natural)
Ambergris
Ambra grisea (Metabolic byproduct)
Coral (Precious Coral)
Corallium rubrum (Red Coral), Paracorallium japonicum (Momo Coral), Pleurocorallium elatius (Sardinian Coral), various other species within the Corallidae family. Chemically, it's primarily Calcium Carbonate (CaCO 3 ).