Sedimentary Rock Or Mineral (Depending On Origin And Purity)

Fossilized Tooth

Vertebrate Fossilized Tooth (Mineralized Biogenic Material)

Yellow Quartz / Chalcedony

Silicon Dioxide (SiO2)

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.

River Stone / Pebble

Clastic Sediment (composed largely of Quartz, Feldspar, and various rock fragments)

Sandstone

Arenite (primarily Quartz, SiO2)

Sandstone

Sedimentary Rock (Quartz Sandstone)

River Gravel

Polymictic Gravel / Detrital Rock Aggregate

Amber Dragonfly Brooch

Succinited (Baltic Amber)

Weathered iron-rich sandstone or lateritic rock

Ferruginous sandstone/laterite; chiefly quartz (SiO₂) with iron oxides such as hematite and goethite

Ironstone Concretion (Limonite/Goethite)

Ironstone (composed primarily of Goethite FeO(OH) and Limonite)

Quartz (Common Quartz/Citrine-toned)

Silicon Dioxide (SiO2)

Dinosaur Fossil Tooth

Vertebrate Fossilized Tooth

White Agate (Chalcedony)

Silicon Dioxide (SiO2)

Rough Amber (likely Copal or immature Amber)

Organic gemstone / Succinite (if Baltic)

Sandstone (Flagstone)

Arenite (composed primarily of SiO2)

Gold Flake / Placer Gold

Native Gold (Au)

Fluorite

Calcium Fluoride (CaF2)

Quartz

Silicon Dioxide (SiO₂)

Breccia

Clastic Breccia

Diamond

Native Carbon (C)

Sandstone (likely Quartzose Sandstone)

Arenite (composed primarily of SiO2)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily Quartz - SiO2)

Quartz Geode or Druzy Quartz in Host Rock

Silicon Dioxide (SiO2)

Jasper (likely a variety of Yellow or Mustard Jasper)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Conglomerate

Conglomerate Rock

Hag Stone

Porous sedimentary rock (typically Flint, Chert, or Sandstone) with naturally occurring holes

Sandstone

Clastic sedimentary rock (Quartz arenite / Arkose)

Amber

Fossilized Tree Resin

Sandstone (likely Quartzose Sandstone with mineral staining)

Arenite (composed mainly of SiO2)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Boxwork or Septarian Concretion

Septarian nodule / Boxwork weathering

Halite (Rock Salt)

Halite (Sodium Chloride, NaCl)

Pebble (likely Quartzite or Chert)

Clastic Sediment, potentially composed of SiO₂ (Quartz)

Green Fluorite

Calcium Fluoride (CaF2)

Schist

Metamorphic Rock (Schist)

Travertine

Calcareous Tufa (CaCO3)

Fluorite Octahedron

Fluorite (Calcium Fluoride, CaF2)

Sandstone

Sedimentary Clastic Rock (Quartz Arenite)

Sandstone

Sedimentary Rock (Quartz arenite/Arkose)

Asphalt (Bituminous Pavement Bit)

Bitumen-bound aggregate (Petrochemical-bound composite)

Sandstone

Arenite (primarily SiO2)

Agate (Chalcedony)

Cryptocrystalline Silica or Silicon Dioxide (SiO2)