Mineral In Metamorphic Rock

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Sedimentary/Metamorphic Matrix

Corundum (Sapphire in Host Rock)

Corundum (Aluminum Oxide, Al2O3)

Greenschist (Chlorite Schist)

Greenschist (containing chlorite, actinolite, and epidote)

Quartzite with Iron Mineral Banding

Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3) staining

Coarse Sand Grain / Lithic Fragment

Clastic Sediment (Lithic fragment or Quartz/Feldspar grain)

Epidote in Quartz

Quartz with Epidote inclusions (SiO2 with Ca2(Al,Fe)3(SiO4)3(OH) inclusions)

Gneiss (specifically a weathered Amphibolite or Garnet Gneiss)

Gneiss (complex silicate composition)

Agate

Silicon Dioxide (SiO2) - Chalcedony variant

Quartzite with inclusions

Quartzite (primarily SiO2)

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Given the appearance, it's likely a fragment of an igneous or metamorphic rock composed of multiple minerals. Without specific diagnostic features, it's difficult to give a common name other than 'crystalline rock fragment'. If pressed to guess based on the granular, somewhat light and dark speckled appearance, it could be a fragment of granite or a related intrusive igneous rock.

As a rock fragment, it does not have a single scientific mineral name; rather, it's a piece of a rock which is a combination of minerals. If it were granite, its main mineral composition would be quartz (SiO2), feldspar (e.g., KAlSi3O8 - orthoclase, (Na,Ca)(Al,Si)4O8 - plagioclase), and mica (e.g., KAl2(AlSi3O10)(OH)2 - muscovite or K(Mg,Fe)3AlSi3O10(OH)2 - biotite), among others.

Yellow Quartz (Citrine Quartz Pebble)

Silicon Dioxide (SiO2)

Schist

Schist (various mineral compositions)

Serpentine (Serpentinite)

Serpentinite (complex silicate group including lizardite, chrysotile, and antigorite)

Quartz (Pebble)

Quartz (SiO₂)

Fuchsite on Quartz

Muscovite (KAl2(AlSi3O10)(OH)2) with Chromium impurities

Marble

Recrystallized Calcite (CaCO3) Rock

Schist (Micaceous Schist)

Schist (containing mainly Muscovite and Quartz)

Granitic Gneiss

Gneiss (High-grade regional metamorphic rock)

Quartz Vein in Metamorphic Rock

Silicon Dioxide (SiO2) within Metasedimentary host

Agate (Geode nodule)

Cryptocrystalline Quartz (SiO2)

Gneiss

Gneiss (High-grade regional metamorphic rock)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Schist

Mica Schist

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Lapis Lazuli

Complex mixture of minerals (lazurite, calcite, pyrite, and sodalite); (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2

Quartzite

Quartzite (primarily SiO2)

Lapis Lazuli

Lazurite-rich metamorphic rock ((Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Blue Sapphire

Corundum (Al2O3 - Aluminum Oxide with Iron and Titanium impurities)

Peacock Ore (Bornite or Iridescent Chalcopyrite)

Bornite (Cu5FeS4) or Chalcopyrite (CuFeS2) with oxidation

Prehnite

Prehnite Ca2Al2Si3O10(OH)2

Banded Chalcedony (Agate)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Green Agate

Silicon Dioxide (SiO2) - Chalcedony variety

Pyrite

Iron Disulfide (FeS2)

Quartz

Quartz (SiO₂ - Silicon Dioxide)

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

Clear Quartz Crystal

Silicon Dioxide (SiO2)

Eclogite

Eclogite (Pyrope garnet and Omphacite pyroxene)

Serpentinite (Serpentine Rock)

Primarily composed of serpentine group minerals, such as antigorite, chrysotile, and lizardite. Chemical formula for serpentine minerals is (Mg,Fe)3Si2O5(OH)4.

Ruby in Zoisite

Ruby (Corundum, Al2O3) in Zoisite (Calcium aluminum silicate hydroxide, Ca2Al3(SiO4)3(OH)) with some Hornblende