Igneous Rock

Granite

Phaneritic intrusive igneous rock (composed mainly of Quartz SiO2, Feldspar KAlSi3O8, and Biotite/Mica)

Nuummite

Nuummite (Orthoamphibole rock composed of Anthophyllite and Gedrite)

Larvikite

Monzonite (intermediate intrusive igneous rock containing plagioclase, alkali feldspar, and minor dark minerals)

Slag (Industrial Byproduct)

Anthropogenic Vitreous Silicate material

Black Obsidian

Volcanic Glass (predominantly SiO2, Silicon Dioxide)

Obsidian

Obsidian (Volcanic Glass, primarily SiO2)

Basalt (Vesicular)

Extrusive mafic igneous rock; primarily (Mg, Fe)2SiO4 (Olivine), CaAl2Si2O8 (Plagioclase Feldspar), and Pyroxene

Granite

Granite

Granite

Granite (a common rock type, not a single mineral with a formula. Composed primarily of quartz, feldspar, and mica/amphibole).

Druzy Quartz on Host Rock

Silicon Dioxide (SiO2) with various iron-oxide inclusions

River Rock (Basalt)

Basalt (SiO2 range: 45-52%)

Unakite (often traded as Dragon Blood Jasper)

Epidotized Granite

Basalt Pebble

Extrusive mafic igneous rock; primarily (Ca, Na)(Mg, Fe, Al)Si2O6 and (Ca, Na)AlSi3O8

Granite with Biotite and Quartz

Phaneritic Felsic Igneous Rock (composed of SiO2, KAlSi3O8, and K(Mg,Fe)3AlSi3O10(OH)2)

Granite Cobble

Felsic intrusive igneous rock (composition: SiO₂ with KAlSi₃O₈, NaAlSi₃O₈, and CaAl₂Si₂O₈)

Lapis Lazuli

Lapis Lazuli (a rock composed primarily of Lazurite (Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2, with varying amounts of Calcite, Pyrite, and Sodalite).

Black Obsidian

Obsidian, SiO2 (amorphous)

Granite

Phaneritic Igneous Rock (composed primarily of Quartz SiO2, Alkali Feldspar (K,Na)AlSi3O8, and Plagioclase Feldspar)

Granite

Granite (phaneritic intrusive igneous rock consisting of 20-60% quartz, orthoclase/plagioclase feldspar, and mica/amphibole)

Obsidian

Obsidian (volcanic glass)

Granite

Granite (a common rock type, not a single mineral species)

Rose Quartz

Quartz (SiO₂), specifically a variety of Quartz

Rose Quartz

Rose Quartz (SiO2)

Granite Cobble/Pebble

Granite

Granite (with Muscovite Mica)

Phaneritic Felsic Igneous Rock (primarily Quartz SiO2, K-Feldspar KAlSi3O8, and Muscovite KAl2(AlSi3O10)(OH)2)

Peridot (likely, based on color and appearance)

Olivine group mineral, specifically (Mg,Fe)2SiO4 (Forsterite-Fayalite solid solution series)

Basalt

Extrusive mafic igneous rock; primarily (Ca,Na)(Mg,Fe,Al,Si)2O6 with (Ca,Na)(Al,Si)4O8

Metal Chain (Likely Steel or a Steel Alloy)

Steel (primarily iron and carbon); specific alloy unknown

Granite

Granite

Basalt (Vesicular)

Extrusive mafic igneous rock; primarily (Ca, Na)(Mg, Fe, Al)(Si, Al)2O6 with (Ca, Na)(Al, Si)4O8

Basalt

Basalt

Granite Quartz Blend (Pegmatite or Quartz-rich Granite)

Igneous rock composed primarily of SiO2 (Quartz) with KAlSi3O8 (Feldspar) and (K,Fe,Mg)3(Al,Si4O10)(OH)2 (Biotite)

Quartz

Silicon dioxide (SiO₂)

Basalt

Basalt (dominated by plagioclase feldspar and pyroxene)

Granite

Granite (a common rock name, not a single mineral species, composed primarily of quartz, feldspar, and mica/amphibole)

Basalt with Weathered Surface

Basalt

Basalt

Basalt

Vesicular Basalt

Extrusive mafic igneous rock; primarily (Ca,Na)(Mg,Fe,Al,Si)2O6 (Pyroxene) and (Ca,Na)Al(Al,Si)Si2O8 (Plagioclase Feldspar)

Diamond

Diamond (pure carbon; C)

Diamond

Diamond (Carbon, C)

Diamond

Diamond (carbon allotrope), C (chemical formula)

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.