Metamorphic Rock (Variety Of Quartz)

Labradorite (Feldspar)

Labradorite: (Ca,Na)(Al,Si)4O8

Smoky Quartz in Matrix

Silicon dioxide (SiO2) within Pegmatite/Gneiss

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

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.

Aventurine

Silicon Dioxide (SiO2 with inclusions of Fuchsite mica)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide) - SiO2

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron inclusions)

Mica Schist

Mica Schist (primarily composed of Muscovite, Biotite, and Quartz)

Granite

Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Agate (Carnelian / Chalcedony)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Vesicular Basalt

Vesicular Basalt (Aphanitic Mafic Rock)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Blue Chalcedony

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Granite

Phaneritic Felsic Igneous Rock (Granite)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (primarily Quartz / Chalcedony: SiO2)

Pyrite

Iron Pyrite (FeS2)

Chert (Jasper/Mudstone)

Microcrystalline Quartz (SiO2)

Rutilated Quartz

Quartz (SiO2) with Rutile (TiO2) inclusions

Chert Pebble/Nodule

Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)

Yellow Quartz Pebble

Silicon Dioxide (SiO2)

Chert (or Flint)

Chert (a cryptocrystalline variety of quartz, SiO2)

River Quartz Pitting / Quartzite Pebble

Quartzite (primarily SiO2)