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

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

Lapis Lazuli (Tumbled Specimen)

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

Lapis Lazuli

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

Lapis Lazuli

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

Lapis Lazuli (polished cabochon)

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

Lapis Lazuli

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

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

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

Lapis Lazuli

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

Lapis Lazuli

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

Lapis Lazuli (Lazurite crystals on Marble)

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

Unakite

Epidotized Granite

Lapis Lazuli

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

Unakite

Epidotized Granite

Mixed Tumbled Stones Collection

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

Agate

Silicon Dioxide (SiO2) - variety of Chalcedony

Marble

Recrystallized Calcite (CaCO3)

Yellow Quartzite River Cobble

Meta-quartzite (SiO2 with iron oxide staining)

Quartz (likely) or a Quartzite Pebble

Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated Iron Oxide)

Quartzite (River Cobble)

SiO2 (Quartz-rich Metamorphic Rock)

Lapis Lazuli (polished cabochon/sphere)

Na8[Al6Si6O24]Sn with accessory minerals (Pyrite, Calcite)

Ventifact

Eolian Ventifact (often composed of basalt, chert, or quartzite)

Riverstone Quartzite (Water-worn Siltstone/Quartzite)

Metamorphosed Quartz-rich Arenite (SiO2)

Lapis Lazuli (Raw)

Lazurite-rich metamorphic rock; Na3Ca(Al3Si3O12)S

Lapis Lazuli

Lapis Lazuli (Rock composed primarily of Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, Calcite, and Pyrite)

Quartzite Pebble

Quartzite (SiO2)

Satin Spar (Gypsum)

Hydrous Calcium Sulfate (CaSO4·2H2O)

Gneiss (specifically Granitic Gneiss)

Gneiss (composed primarily of Quartz, Feldspar, and Biotite/Amphibole)

Dalmatian Stone

Dalmatian Jasper (a misnomer for an Aplite with Arfvedsonite spots)

Serpentinite

Serpentinite (composed primarily of minerals in the Serpentine group)

Unakite

Unakite (Metasomatized Granite)

Gneiss (High-Grade Metamorphic Rock)

Gneiss (primarily composed of Quartz, Feldspar, and Mica/Amphiboles)

Gneiss (specifically a Granitic Gneiss)

Gneiss (typically composed of Quartz, Feldspar, and Mica/Amphiboles)

Lapis Lazuli (Low Grade)

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

Orange Calcite (likely polished specimen)

Calcite

Serpentinite

Serpentinite (a rock composed predominantly of serpentine group minerals)

Quartzite (Yellow/Tan)

Metamorphic Rock composed of Quartz (SiO₂)

Slate

Foliated Metamorphic Rock (composed primarily of Quartz, Muscovite, and Illite)