Minerals

Quartz Pebble

Silicon Dioxide (SiO2)

Granitic gneiss (weathered, rounded cobble)

Foliated granitoid; primarily quartz, feldspar, and mica (composition commonly approximates granite)

Pegmatite

Igneous Pegmatite

Epidote-bearing basalt

Basalt with epidote-group mineral inclusions, likely epidote or pistachite (Ca₂(Al,Fe³⁺)₃(SiO₄)₃(OH))

Granitic Gneiss

Gneiss (Metamorphic Rock)

Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Quartz Cluster on Matrix

Silicon Dioxide (SiO2)

Mica-rich schist (likely biotite–muscovite schist)

Mica schist; composed chiefly of muscovite and/or biotite with quartz and feldspar

Small brown mineral or rock fragment

Undetermined; the image does not show enough diagnostic detail for reliable identification

Likely a small rough mineral specimen

Unidentifiable from the image; possibly a mica-bearing rock or green mineral

Quartz-rich pegmatite fragment

Granite/pegmatite; chiefly quartz (SiO₂) and feldspar, with possible biotite or tourmaline

Schist with Biotite and Quartz

Biotite-Quartz Schist (Fe,Mg,Al silicate mix)

Weathered copper-bearing volcanic rock (likely altered basalt/andesite)

Hydrothermally altered basalt or andesite; green coloration may reflect chlorite, epidote, or copper minerals such as chrysocolla

Mineral, possibly rock fragment containing a mineral

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.

Banded quartz-rich rock (possibly pegmatite)

Likely quartz–feldspar pegmatite; identification is tentative from the photo

Sulfur

Sulfur (S8)

Limonite/Goethite on Shale

Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock

Iron-stained Quartz (Gossan/Limonite-coated Quartz)

Silicon Dioxide (SiO2) with Hydrated Iron Oxides (FeO(OH)·nH2O)

Malachite or Chrysocolla on Host Rock

Cu2(CO3)(OH)2 (Malachite) or (Cu,Al)2H2Si2O5(OH)4 (Chrysocolla)

Liesegang Banded Sandstone (Wonderstone)

Ferruginous Sandstone with Liesegang Rings

Mineral Specimens and Streak Test

Various Minerals (Silicates, Carbonates, Oxides)

Weathered copper-bearing rock, possibly malachite/chrysocolla-bearing matrix

Indeterminate; likely copper carbonate/silicate minerals in a host rock, potentially malachite (Cu₂CO₃(OH)₂) or chrysocolla (hydrated copper silicate)