Igneous, Sedimentary, Metamorphic, And Mineral

Orange Quartz (Citrine Quartz)

Silicon Dioxide (SiO2) with iron impurities

Green Kyanite

Kyanite (Al2SiO5)

Mixed Gemstone Beaded Jewelry

Various minerals (e.g., Quartz varieties like Rose Quartz, Amethyst; Peridot; Garnet; etc.)

Dragon Blood Jasper

Epidote-containing Quartz Chalcedony (SiO2 with Ca2(Al, Fe)3(SiO4)3(OH))

Quartz Pebble (often referred to as 'Sea Glass' or 'River Stone' when worn smooth)

Silicon Dioxide (SiO2)

Milky Quartz (Water-Worn Pebble)

Silicon Dioxide (SiO2)

Yellow Calcite

Calcium Carbonate (CaCO3)

Greenschist

Greenschist (composed of Chlorite, Actinolite, and Epidote)

Quartz

Silicon Dioxide (SiO2)

Red Garnet (Pyrope or Almandine)

Magnesium aluminum silicate (Mg3Al2(SiO4)3) or Iron aluminum silicate (Fe3Al2(SiO4)3)

Schorl (Black Tourmaline)

Sodium Iron Aluminum Borosilicate Hydroxide; NaFe2+3Al6Si6O18(BO3)3(OH)3OH

Emerald

Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities

Mica in Quartz Host

Muscovite (KAl2(AlSi3O10)(OH)2) in Quartz (SiO2)

Green Aventurine

SiO2 (Silicon Dioxide with inclusions of Fuchsite mica)

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)

Galena

Lead(II) sulfide (PbS)

Yellow Aventurine

Silicon Dioxide with inclusions (SiO2 + Muscovite/Fuchsite)

Gneiss

High-grade foliated metamorphic rock

Corundum (Ruby variety)

Aluminium oxide (Al2O3)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Dalmatian Stone

Peralkaline rhyolite

Banded Gneiss

Gneiss

Quartz

Quartz (SiO2 - Silicon Dioxide)

Sapphire

Corundum (Al2O3)

Kyanite in Quartz

Kyanite (Al2SiO5) with Quartz (SiO2)

Biotite (Black Mica)

Biotite - K(Mg,Fe)3(AlSi3O10)(F,OH)2

Garnet (Almandine)

Almandine Garnet (Fe3Al2(SiO4)3)

Pyrite in Matrix (often with Chalcopyrite)

Iron Sulfide (FeS2) / Copper Iron Sulfide (CuFeS2)

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.

Ruby (Corundum)

Aluminum Oxide (Al2O3) with Chromium traces

Clear Quartz

Silicon Dioxide (SiO2)

Garnet

Garnet group (X3Y2(SiO4)3)

Quartz / Quartz Cluster

Silicon Dioxide (SiO2)

Potassium Feldspar (Orthoclase)

KAlSi3O8 (Potassium Aluminum Silicate)

Gemstone Sand (Mineral Assortment)

Mixed Mineral Concentrates (Commonly including Quartz SiO2, Garnet X3Y2(SiO4)3, and Tourmaline (Na,Ca)(Li,Mg,Al)3(Al,Fe,Mn)6(BO3)3(Si6O18)(OH,F)4)

Peacock Ore

Bornite (Cu5FeS4)

Rose Quartz

Rose Quartz (SiO2)

Rhodonite

Manganese Inosilicate (Mn,Fe,Mg,Ca)SiO3

Greenstone (Greywacke or Nephrite Jade variant)

Metamorphosed mafic igneous or sedimentary rock (e.g., Actinolite-Chlorite Schist)

Calcite

Calcite (Calcium Carbonate, CaCO3)

Chlorite Included Quartz

Silicon Dioxide (SiO2) with Chlorite (Mg,Fe,Li)6AlSi3O10(OH)8

Smoky Quartz

Silicon Dioxide (SiO2)