Mineral (Native Element Alloy)

Blue Quartz

Silicon Dioxide (SiO2) with inclusions

Quartz

Silicon Dioxide (SiO2)

Garnet (Almandine)

Almandine (Fe3Al2(SiO4)3)

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Goethite/Hematite Nodule

Goethite (FeO(OH)) and Hematite (Fe2O3)

Gossan (with Limonite/Hematite coating)

Ferruginous Gossan (Fe2O3·nH2O / Fe2O3)

Limonite (Yellow Ochre)

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

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Lapis Lazuli

Lapis lazuli (Complex silicate rock containing Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, Calcite, and Pyrite)

Quartz pebble

Silicon dioxide (SiO2)

Limonite / Ironstone Nodule

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

Lapis Lazuli (Tumbled Specimen)

Lapis Lazuli (Aggregate rock containing Lazurite: (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2)

Bauxite

Bauxite (Aluminum Ore)

Greenstone

Metabasalt / Chlorite Schist

Limonite/Ironstone

Limonite (FeO(OH)·nH2O)

Aventurine (likely Green Aventurine)

Silicon Dioxide (SiO2) with mineral inclusions

Sandstone

Arenite (composed primarily of SiO2)

Granite

Intrusive Igneous Rock

Granite (Gneissic / Weathered Pebble)

Felsic intrusive igneous rock (Granite)

Gneiss

Gneiss

Gneiss

Gneiss

Diorite

Diorite

Banded Gneiss

Gneiss (High-grade Metamorphic Rock)

Gneiss (specifically a weathered Amphibolite or Garnet Gneiss)

Gneiss (complex silicate composition)

Banded Gneiss

Gneiss (Metamorphic Rock)

Chrysocolla

Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)

Larimar

Blue Pectolite (NaCa2Si3O8(OH))

Graphic Granite

Pegmatitic Granite

Limonite (Iron Ore)

Limonite (unstructured hydrated iron(III) oxide-hydroxides, often FeO(OH)·nH2O)

Sandstone

Arenite (Siliclastic sedimentary rock), SiO2 + various minerals

Granite

Intrusive Igneous Rock

Porphyritic Igneous Rock with Iron Oxide Weathering

Weathered Porphyry (containing Quartz, Feldspar, Amphibole/Biotite, and Hematite/Limonite)

Rhodochrosite

Rhodochrosite (MnCO3)

Chrysocolla

Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)

Granite Gneiss

Gneiss (High-grade regional metamorphic rock)

Gneiss

Gneiss (High-grade 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.

Sandstone (with Iron Staining)

Sandstone (mainly Quartz, SiO2, with Iron Oxides like Goethite/Hematite)

Likely serpentinized ultramafic rock (serpentinite)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, possibly with magnetite, chromite, and brucite

Granodiorite

Granodiorite (Intermediate intrusive igneous rock)