Ambergris
Ambergris (Coprolite-adjacent organic substance)
Organic (Geological interest)
Category
Organic Gemstone (Often Associated With Sedimentary Sequences)
Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Garnet Schist
Garnet-bearing Mica Schist (variety of compositions, often Al2SiO5 with X3Y2(SiO4)3)
metamorphic
Emerald
Beryl (Be3Al2(SiO3)6) with trace Chromium/Vanadium
mineral
Black Tourmaline (Schorl)
Schorl (Na(Fe^2+)3Al6(Si6O18)(BO3)3(OH)4)
Mineral
Moss Agate
Chalcedony (Silicon Dioxide with inclusions) - SiO2
mineral
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
mineral
Amber
Succinite (Fossilized Tree Resin) - C10H16O
mineral
Metal Alloy (Likely Pewter or Sterling Silver)
Not a natural geological specimen; composed of refined metals. If pewter, it's a tin-based alloy. If sterling silver, it's 92.5% silver and 7.5% other metals (usually copper).
Man-made material (metal)
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Caribbean Calcite
Calcium Carbonate with Argonite (CaCO3)
mineral
Green Aventurine
Aventurine (Silicon dioxide, SiO₂)
Mineral; variety of Quartz
Tektite (specifically Indochinite)
Tektite (Natural silica glass)
Mineraloid (Impact glass)
Sunstone
Aventurine Feldspar (Plagioclase Feldspar with inclusions)
mineral
Citrine
Citrine (Silicon Dioxide, SiO2)
mineral
Fossil Shell (Bivalve)
Class Bivalvia (Likely a member of the Ostreidae or Gryphaeidae family), CaCO3
sedimentary
Nephrite (a form of Jade)
Nephrite (a variety of the mineral actinolite, Ca2(Mg,Fe)5Si8O22(OH)2)
Mineral
Granite
Granite (a common rock type, not a single mineral species)
Igneous
Emerald In Matrix
Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium
mineral
![Banded Iron Formation (BIF) (Banded Iron Formation (composed primarily of Hematite [Fe2O3], Magnetite [Fe3O4], and Chert [SiO2])) — sedimentary](https://media.rockidentification.com/31228b61-1a48-4b85-8684-c24240e51d92-thumbnail.jpg)
Banded Iron Formation (BIF)
Banded Iron Formation (composed primarily of Hematite [Fe2O3], Magnetite [Fe3O4], and Chert [SiO2])
sedimentary
Chert (Jasper/Agate variety)
Microcrystalline quartz (SiO2)
sedimentary
Chert (Jasper Variant likely)
Silicon Dioxide (SiO2)
Sedimentary Rock or Mineral (depending on origin and purity)
Ironstone Concretion / Limonite-stained Siltstone
Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)
sedimentary
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral
Quartz (possibly milky quartz or quartz with inclusions)
SiO2 (Silicon Dioxide)
Mineral
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood (SiO2)
metamorphic
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
mineral
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
metamorphic
Septarian Nodule or Mud Crack Fossil
Septarian Nodule (Concretion)
sedimentary
Jasper (Mookaite variety likely)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Garnet-bearing Schist
Almandine Garnet (Fe3Al2(SiO4)3) in Mica Schist
metamorphic
Aquamarine
Beryl (Be3Al2Si6O18)
mineral
Raw Emerald in Matrix
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
mineral
Labradorite (a variety of Feldspar)
Labradorite; (Na,Ca)(Al,Si)4O8 (a plagioclase feldspar)
igneous
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Garnet Schist
Almandine-Muscovite Schist
metamorphic
Shale with Siltstone layering
Sedimentary Clastic Rock (Mudstone/Shale)
sedimentary
Zoisite with Ruby / Anyolite
Anyolite (Ca2Al3(SiO4)3(OH) with Chromian Zoisite and Tschermakite inclusions)
metamorphic
Citrine Quartz
Silicon Dioxide (SiO2) with iron impurities
mineral
Fossilized Sand Tiger Shark Tooth
Carcharias taurus / Striatolamia macrota (mineralized as Hydroxylapatite/Francolite)
sedimentary (fossil)
Amber
Fossilized Tree Resin (Amorphous Hydrocarbon)
Mineral