Metamorphic Rock (Composed Of Multiple Minerals)

Ruby in Zoisite

Ruby (α-Al2O3) embedded in Zoisite (Ca2Al3(SiO4)3(OH)) with some Hornblende

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.

Lapis Lazuli (in Matrix)

Lazurite-bearing Metamorphic Rock (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2

Lapis Lazuli

Na8[Al6Si6O24]n(S,Cl,SO4,OH)2

Lapis Lazuli (Low-grade)

Lapis Lazuli (Aggregate of Lazurite, Calcite, and Pyrite)

Lapis Lazuli

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

Lapis Lazuli (Tumbled Specimen)

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

Lapis Lazuli

Lazurite-rich metamorphic rock

Lapis Lazuli

Lazurite (primary mineral component), (Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2

Lapis Lazuli (polished cabochon)

Lazurite-rich metamorphic rock (approx. Na6Ca2Al6Si6O24(SO4,S,Cl)2)

Lapis Lazuli

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

Lapis Lazuli

Lapis Lazuli (Primary mineral: Lazurite, (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Lapis Lazuli

Lapis Lazuli (Mineral composition: Lazurite, Calcite, Sodalite, and Pyrite)

Lapis Lazuli

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

Lapis Lazuli

Sodium aluminum silicate with sulfur (main component: Lazurite [(Na,Ca)8(AlSiO4)6(SO4,S,Cl)2])

Lapis Lazuli (Lazurite crystals on Marble)

Lazurite / (Na,Ca)8[(S,Cl,SO4,OH)2|(AlSiO4)6]

Lapis Lazuli

Lapis Lazuli (A complex rock primarily composed of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Lapis Lazuli

Lapis Lazuli (Mineral composition: Lazurite (Na,Ca)8(AlSiO4)6(SO4,S,Cl,OH)2, Calcite, and Pyrite)

Lapis Lazuli

Na8[Al6Si6O24]S2 (Lazurite component), a rock composed primarily of Lazurite, Calcite, and Pyrite

Lapis Lazuli

Lapis Lazuli (Complex aggregate mainly of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Lapis Lazuli

Lazurite-rich metamorphic rock ((Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Unakite

Epidotized Granite

Lapis Lazuli

Na8(Al6Si6O24)S2 (Lazurite is the primary constituent mineral)

Unakite

Epidotized Granite

Botryoidal Chalcedony (Agate)

Silicon Dioxide (SiO2)

Lapis Lazuli

(Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2 (Complex silicate rock)

Quartz pebble

Silicon dioxide (SiO2)

Lapis Lazuli

(Na,Ca)8(AlSiO4)6(SO4,S,Cl)2 (Complex silicate rock)

Sandstone (Pebble / Cobble)

Arenite / Sedimentary Rock (composed of quartz and feldspar)

Pearl-bearing oyster shell

Nacreous shell, primarily aragonite (CaCO₃), with natural pearls (calcium-carbonate nacre)

Quartz Pebble

Silicon Dioxide (SiO2)

Schist

Schist

Likely banded gneiss or mica-rich metamorphic pebble

Gneiss; composition likely quartz, feldspar, and biotite/muscovite mica

Uncertain small stone; possibly weathered quartz-bearing rock

Indeterminate from image; candidate materials include quartz-rich pebble or altered silicate rock

Mixed Tumbled Stones Collection

Mixed Silicates and Carbonates (Quartz, Amorphous Silica, Carbonates)

Gneiss boulder

Banded granitoid gneiss; chiefly quartz, feldspar, and biotite/hornblende

Dark, coarse-grained rock (possibly diorite or amphibolite)

Undetermined; likely a mafic to intermediate rock containing plagioclase and dark amphibole or pyroxene

Weathered granite pebble

Granite, a coarse-grained felsic intrusive igneous rock

Lapis Lazuli

Lapis Lazuli (Primary mineral: Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Mixed rounded gravel and weathered rock fragments

Polymictic alluvial or glacial gravel; composition appears to include basaltic, quartz-rich, and feldspathic clasts

Banded gneiss (possibly migmatitic gneiss)

Quartz–feldspar–mica gneiss; composition commonly includes quartz, feldspar, biotite/hornblende, and accessory dark minerals

Mixed collection of common river stones

Varied lithologies, visibly including quartz-rich rock, dark mafic rock, sandstone, and purple quartz-bearing material