Chert (Jasper type)
Microcrystalline Quartz (SiO2)
Category
Browse organic gemstone (not a rock) specimens identified by the Rock Identifier community.
Chert (Jasper type)
Microcrystalline Quartz (SiO2)
Pyrite on Limestone
Iron Disulfide (FeS2) in Calcium Carbonate (CaCO3) matrix
Amber
Succinite (C10H16O)
Fossilized Shell in Limestone
Bivalve fossil (CaCO3) in Carbonate Sedimentary Rock
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions of Chlorite, Manganese, or Iron
Blue Sapphire
Corundum (Al2O3)
Jasper (Red Jasper)
Silicon Dioxide (SiO₂)
Shale
Shale (fine-grained clastic sedimentary rock)
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Agate Geode Slice (with Druzy Quartz)
Silicon Dioxide (SiO2)
Chert (Flint)
Microcrystalline Opaline Silica (SiO2)
Chert (often called Flint or Jasper based on color)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (and Flint variant)
Microcrystalline Quartz (SiO2)
River Rock
Sedimentary Rock (various compositions)
Rose Quartz
Silicon dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Glauconitic Sandstone (Greensand)
Glauconitic Quartz Arenite (containing Glauconite, (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
Serpentine (Serpentinite)
Antigorite, Lizardite, or Chrysotile; (Mg,Fe)3Si2O5(OH)4
Petrified Wood
Silicified wood (principally SiO2)
Red Chert (Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Chert (often called Flint)
Microcrystalline Quartz (SiO2)
Manganese-coated Sandstone
Clastic sedimentary rock with Manganese Oxide (often Pyrolusite or Psilomelane)
Chert / River Jasper
Microcrystalline Quartz (SiO2)
Chert (Common Opal/Jasper variety)
Microcrystalline Quartz (SiO2) with hydration
Chert (specifically Flint or Novaculite variant)
Chert (Microcrystalline Quartz, SiO2)
Amber
Succinite (organic mineraloid); Chemical formula: C10H16O
Shale (sub-type: Carbonaceous Shale)
Lutaceous Sedimentary Rock
Chert (Quartz Variety)
Chert (mostly SiO2 / Silicon Dioxide)
Fossilized Horn Coral
Order Rugosa (Rugose Coral)
Chert (often called Jasper or River Rock)
Chert (SiO2)
Moss Agate
Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)
Petrified Wood
Silicified Wood (SiO2)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide
Amber
Fossilized Tree Resin (Succinate)
Chert (variously identified as Flint)
Microcrystalline Quartz (SiO2)
Amber
Succinite (fossilized resin)
Chert (variant Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sandstone Chert Concretion
Silica-cemented Concretion (primarily SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Chert (Chert / Flint)
Silicon dioxide (SiO2) - Microcrystalline quartz
Chert (Nodule)
Silicon Dioxide (SiO2)