Chert (Yellow Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Category
Organic (Often Found By Beachcombers)
Browse organic (often found by beachcombers) specimens identified by the Rock Identifier community.
Yellow Quartzite (River Pebble)
Quartzite (SiO2 with iron oxide impurities)
metamorphic
Conglomerate
Clastic Sedimentary (Conglomerate)
sedimentary
Green Quartzite
Quartzite (primarily SiO2 with chlorite inclusions)
metamorphic
Crinoid Stem Fossil
Class Crinoidea (Phylum Echinodermata), often preserved in Limestone or Calcite (CaCO3)
sedimentary
Green Aventurine in Host Rock
SiO2 (Quartz with Fuchsite inclusions)
mineral
Echinoid Fossil (Sea Urchin Fossil)
Echinoidea (phylum Echinodermata), often preserved as Calcite (CaCO3)
sedimentary
Chert (Common Opal/Agate inclusion)
Microcrystalline Quartz (SiO2)
sedimentary
Travertine (Tufa)
Chemical Sedimentary Limestone (CaCO3)
sedimentary
Amygdaloidal Basalt
Amygdaloidal Basalt with Secondary Infilling (e.g., Agate, Quartz, or Zeolite)
igneous
Echinoidea (Fossil Sea Urchin)
Echinodermata Echinoidea
sedimentary
Red Quartz (Druzy)
Silicon Dioxide (SiO2) with Hematite inclusions
mineral
Gold Ore (in Quartz/Sulfide matrix)
Native Gold (Au) in Quartz (SiO2) and Pyrite (FeS2)
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Banded Agate (Pink/White)
Silicon Dioxide (SiO2) - Variety of Chalcedony
mineral
Epidote in Matrix (Dragon Stone variant)
Epidote with Quartz/Feldspar (Ca2(Al,Fe)3(SiO4)3(OH))
metamorphic
Arsenopyrite in Quartz/Host Rock
Arsenopyrite (FeAsS)
mineral
Quartz / Quartzite
Silicon Dioxide (SiO2)
metamorphic
Granite
Phaneritic plutonic rock (composed of Quartz, Feldspar, and Mica/Amphibole)
igneous
Iron-stained Quartzite
Metamorphic Quartz (SiO2) with limonite/hematite staining
metamorphic
Almandine Garnet
Iron aluminum silicate (Fe3Al2(SiO4)3)
Mineral
Quartzite pebble
Quartzite (primarily SiO2)
metamorphic
Sandstone (likely Arkosic or Quartzose)
Sandstone (SiO2 dominated)
sedimentary
Rose Quartz
Quartz (Silicon Dioxide - SiO2)
mineral
Agate (Lace Agate Geode Slice)
Silicon Dioxide (SiO2)
mineral
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide mixture)
mineral
Chalcedony (Blue/Grey Lace Agate)
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Rose Quartz
Silicon Dioxide (SiO2) with trace titanium, iron, or manganese
mineral
Quartzite
Quartzite (primarily SiO2)
metamorphic
Quartz (River Pebble)
Silicon Dioxide (SiO2)
mineral
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
mineral
Inspirational River Stone (Quartzite)
Metamorphosed Quartz-rich Rock (Quartzite) with SiO2 composition
metamorphic
Quartzite pebble
Metamorphic rock (mainly SiO2)
metamorphic
Alexandrite
Chrysoberyl (BeAl2O4 with Chromium impurities)
mineral
Glauconite
(K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Rose Quartz
Silicon Dioxide (SiO2)
mineral
Rhodonite
Manganese silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Sandstone (Quartzose Sandstone)
Arenite
sedimentary
Chert (Nodule)
Chert (Silicon Dioxide, SiO2)
sedimentary