Igneous And Mineral

Pyrite (on Shale/Matrix)

Iron Disulfide (FeS2)

Sunstone

Plagioclase Feldspar (Na, Ca)(Al, Si)4O8 with Hematite or Copper inclusions

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Agate

Banded Chalcedony (SiO2 - Silicon Dioxide)

Hematite

Iron(III) oxide (Fe2O3)

Quartz Pebble (Iron-Stained)

Silicon Dioxide (SiO2)

Granitic Pegmatite

Pegmatite (composed primarily of Quartz, Feldspar, and Muscovite mica)

Gneiss

Gneiss (High-grade regional metamorphic rock)

Smoky Quartz

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.

Pink Granite

Phaneritic Felsic Igneous Plutonic Rock

Granite

Granite (Phaneritic intrusive igneous rock)

Clear Quartz

Silicon Dioxide (SiO2)

Aquamarine

Beryl (Be3Al2Si6O18 with iron impurities)

Labradorite

Labradorite (Plagioclase Feldspar Series) - (Ca, Na)(Al, Si)4O8

Amethyst

Amethyst (Silicon Dioxide - SiO2 with iron impurities)

Labradorite

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

Basalt

Extrusive mafic igneous rock

Diorite

Diorite (Intermediate Plutonic Rock)

Diorite

Diorite (Intermediate intrusive igneous rock)

Magnetite with Pyrite or Chalcopyrite inclusions

Magnetite (Fe3O4) with Pyrite (FeS2)

Granodiorite (Water-worn Pebble)

Granodiorite

Granite Cobble

Granitoid (typically containing Quartz SiO2, Feldspar KAlSi3O8, and Mica minerals)

Granite

Granite (composed primarily of Quartz SiO2, Potassium Feldspar KAlSi3O8, and Plagioclase)

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Mahogany Obsidian

Volcanic Glass (with inclusions of Magnetite or Hematite)

Obsidian

Volcanic glass (primary composition: SiO2)

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide)

Obsidian

Volcanic Glass (predominantly SiO2)

Orthoclase (Potassium) Feldspar in Quartz

KAlSi3O8 (Potassium Aluminum Silicate)

Mahogany Obsidian

Volcanic Glass (SiO2 + Fe2O3)

Obsidian

Volcanic Glass (SiO2 - Silicon Dioxide with impurities)

Granite

Granite (Phaneritic intrusive igneous rock)

Banded Gneiss

Gneiss (High-grade Metamorphic Rock)

Granite Cobble

Phaneritic Plutonic Felsic Rock

Granite

Granite (composed primarily of Quartz SiO2, Alkali Feldspar, and Plagioclase Feldspar)

Rough Corundum (likely Sapphire/Zircon-bearing)

Aluminium Oxide (Al2O3)

Granite Pegmatite

Coarse-grained Granite (SiO2 - Aluminum and Alkalies)

Obsidian

Obsidian (principally SiO2)

Mahogany Obsidian

Obsidian (Volcanic Glass with Hematite/Magnetite inclusions), SiO2

Mahogany Obsidian

Volcanic Glass with Hematite inclusions (SiO2)

Obsidian

Obsidian (volcanic glass; primarily SiO2)