Sedimentary Rock (Possibly A Conglomerate Or Coarse Grained Sandstone)

Ironstone Concretions (Ironstone)

Ferruginous Sandstone or Siltstone (Fe2O3)

Opal

Hydrated amorphous silica (SiO2·nH2O)

Granite (Light-colored quartz/feldspar variety)

Granite (composed primarily of Quartz SiO2 and Feldspar KAlSi3O8)

Opal

Hydrated Amorphous Silica (SiO2·nH2O)

Granite

Granite

Granite

Granite

Coarse-Grained Marble

Recrystallized Limestone (Major component: CaCO3)

Granite (Alkali-feldspar Granite)

Granite (composed primarily of Quartz, K-Feldspar, and Plagioclase)

Granite

Granite (composed primarily of Quartz SiO₂, Alkali Feldspar KAlSi₃O–NaAlSi₃O–CaAl₂Si₂O₈, and Plagioclase Feldspar)

Rose Quartz

Quartz (SiO2) with trace elements of titanium, iron, or manganese

Granite

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

Moqui Marble (Concretion)

Iron oxide concretion (Goethite/Hematite and Sandstone)

Diorite (Porphyritic)

Porphyritic Diorite

Limestone

Calcium carbonate (CaCO3)

Granite

Granite (Mainly Quartz, Feldspar, and Mica)

Diorite (Gneissic)

Diorite

Aquamarine

Aquamarine (Beryl variety) - Be3Al2(Si6O18)

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.

Chert (Pink Jasper variant)

Microcrystalline Quartz (SiO2)

Amber

Fossilized tree resin (not a true mineral as it is organic and amorphous); Chemical formula is highly variable, but often approximated as C10H16O.

Limonite Concretion

Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)

Limestone (River Pebble)

Sedimentary Calcium Carbonate (CaCO3)

Ironstone Concretion (Limonite/Goethite)

Ironstone (primarily FeO(OH)·nH2O)

Concrete

Anthropogenic Sedimentary Conglomerate (Cement mixture: typically Ca2SiO4, Ca3SiO5, Ca3Al2O6)

Demantoid Garnet on Matrix

Demantoid (variety of Andradite Garnet) - Ca3(Fe3+)2(SiO4)3

Yellow Quartzite (Onyx Pebble)

Silicon Dioxide (SiO2) - Quartzite

Precious Opal

Hydrated amorphous silica (SiO2·nH2O)

Quartz in Matrix (possibly with Biotite or Hornblende)

Quartz (Silicon Dioxide, SiO2) in Granitic Matrix

Fluorite with Rhodochrosite

Fluorite (CaF2) and Rhodochrosite (MnCO3)

Smoky Quartz

SiO2 (Silicon Dioxide)

Labradorite (likely Black Labradorite or Larvikite)

Labradorite (Na,Ca)(Al,Si)4O8. If a rock, it is typically anorthosite, gabbro, or norite, or a variety of syenite called Larvikite if it is specifically from Larvik, Norway.

Beryl (likely var. Aquamarine or Goshenite) in Matrix

Beryllium Aluminum Silicate (Be3Al2Si6O18)

Quartz (Milky or White Quartz)

Silicon Dioxide (SiO2)

Fossiliferous Limestone (Bivalve Fossil)

Calcium Carbonate (CaCO3) with Bivalvia fossil

Schist

Mica Schist

Ironstone (Limonitic Sandstone)

Ferruginous Sandstone (rich in Limonite: FeO(OH)·nH2O)

Rose Quartz

Rose Quartz (SiO2)

Black Opal

Hydrated Silica (SiO2·nH2O)

Mica Schist

Mica Schist (predominantly Muscovite or Biotite sheet silicates)

Mixed collection of minerals and rocks (Jasper, Carnelian, Granite, and Quartz)

Silicon Dioxide (SiO2) with varying impurities for silicates and igneous aggregates

Shale (or Mudstone)

Siltstone/Argillite (composed mainly of clay and silt-sized particles)

Yellow Jasper

Silicon Dioxide (SiO2) with Goethite/Iron Oxide inclusions