Epidote in Quartz
Quartz with Epidote inclusions (SiO2 with Ca2(Al,Fe)3(SiO4)3(OH) inclusions)
Mineral
Category
Organic (Sedimentary Context)
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Gneiss
Metamorphic Gneiss
metamorphic
Marble
Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.
Metamorphic Rock
Chert (Nodule)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Limestone-based)
Silicon Dioxide (SiO2)
sedimentary
Chert
Chert (microcrystalline quartz, SiO2)
Sedimentary
Chalcopyrite
Chalcopyrite (CuFeS2)
Mineral
Garnet (likely Almandine or a blend)
Garnet group: X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+. Given the dark, somewhat reddish-brown appearance in the image, it's likely Almandine (Fe3Al2(SiO4)3) or a mix with other iron-rich garnets.
Mineral
Chert (variant of Flint)
Chert (SiO2)
Sedimentary
Marble
Marbles are primarily composed of calcite (calcium carbonate, CaCO3) or dolomite (calcium magnesium carbonate, CaMg(CO3)2).
Metamorphic Rock
Quartzite
Quartzite (primarily SiO₂)
metamorphic
Marble
Metamorphosed Limestone/Dolomite
metamorphic
Calcite
Calcite (CaCO3)
mineral
Chert Pebble/Nodule
Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)
Sedimentary
Quartz
Quartz (SiO2, Silicon Dioxide)
Mineral
Rhodonite
Rhodonite, manganese inosilicate — MnSiO₃; the specimen may include quartz, feldspar, and black manganese-oxide minerals in the matrix
mineral
Chert / Flint (a variety of Chert)
Chert (SiO2)
Sedimentary Rock (technically a microcrystalline quartz mineral aggregate)
Calcite
Calcite (Mineral; CaCO₃)
Mineral
Chert (varieties include Flint or Jasper)
Chert (cryptocrystalline quartz; SiO₂)
Sedimentary
Quartz
Quartz (Silicon Dioxide, SiO2)
Mineral
Chert (or Flint)
SiO2 (predominantly microcrystalline quartz)
Sedimentary
Biotite Schist
Biotite Schist
Metamorphic
Chert (Flint)
Chert (microcrystalline quartz)
sedimentary
Calcite
Calcite (Calcium Carbonate, CaCO3)
mineral
Calcite
Calcite (CaCO₃)
Mineral
Calcite
Calcite (CaCO 3)
Mineral
Banded Gneiss
Gneiss (typically quartz, feldspar, mica, amphibole composition)
metamorphic
Banded Gneiss
Gneiss (pronounced "nice")
metamorphic
Chert Pebble (Jasperoid/Flint)
Silicon Dioxide (SiO2) - cryptocrystalline quartz
Sedimentary
Sulfur on Aragonite
Sulfur (S) and Aragonite (CaCO3)
Mineral
Chert (or Flint)
Silicon dioxide (SiO2)
sedimentary
Quartz (chalcedony variety) or Limestone with Quartz Veins
SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)
Mineral or Sedimentary Rock (with mineral inclusions)
Banded Metamorphic Rock (likely Quartzite or Serpentinite/Soapstone)
Metamorphic Rock (possibly a banded Quartzite or a foliated Serpentinite/Talc Schist based on appearance, general term for such a rock is 'Banded Metamorphic Rock' or 'Gneiss' if pronounced banding of different minerals)
Metamorphic
Chert (or possibly Flint)
SiO2 (Silicon Dioxide)
Sedimentary Rock
Chert or Flint (polished/water-worn)
Chert (a microcrystalline or cryptocrystalline variety of quartz, SiO2). Flint is a specific variety of chert.
Sedimentary (most likely, as Chert is a sedimentary rock often found as nodules in limestone or as bedded deposits; however, it can also form by metasomatic replacement, which leans towards metamorphic processes under certain conditions)
Chert (Jasper Variant likely)
Silicon Dioxide (SiO2)
Sedimentary Rock or Mineral (depending on origin and purity)
Banded Iron Formation
Banded Iron Formation (BIF)
Sedimentary