Mineral, Specifically A Rock Fragment

Quartz Crystal Fragment

Silicon Dioxide (SiO2)

Carnelian

Carnelian Chalcedony (SiO2 with Iron Oxide impurities)

Banded Agate

Chalcedony / Silicon Dioxide (SiO2)

Pink Granite

Phaneritic Intrusive Igneous Rock (Granite)

Chalcedony (Botryoidal Agate vein)

Chalcedony (Microcrystalline Quartz) - SiO2

Dalmatian Stone (Dalmation Jasper)

Aplite with Arfvedsonite inclusions

Ocean Jasper

Orbicular Jasper / Chalcedony (SiO2)

Gravel and Sand Aggregate

Unconsolidated Clastic Sediment

Dendritic Agate

Silicon Dioxide (SiO2) with Manganese/Iron inclusions

Agate in Rhyolite

Silicon Dioxide (Quartz/Chalcedony) in Volcanic Rock matrix

Banded Iron Formation (Fragment)

Banded Iron Formation (BIF)

Iron-rich rock fragment (possibly ironstone or limonite/goethite)

Likely ironstone composed largely of goethite/limonite; image alone cannot confirm

Ocean Jasper (Orbicular Jasper)

Silicon Dioxide (SiO2) with various inclusions

Green Aventurine

Aventurine Quartz (SiO2 with inclusions)

Likely quartz-rich pebble fragment

Quartz (SiO₂), possibly milky quartz or quartzite; the photo is insufficient to distinguish them confidently

Herkimer Diamond

Quartz (Silicon Dioxide, SiO2)

Druzy Quartz on Sandstone

Silicon Dioxide (SiO2) on Sedimentary Host Rock

Granite fragment

Granite (Felsic Plutonic Rock)

Milky Quartz

Silicon Dioxide (SiO2)

Dalmatian Stone

Peralkaline Feldsphathic Igneous Rock

Likely iron-rich sandstone or ironstone fragment

Indeterminate ferruginous sedimentary rock; iron oxides may include hematite (Fe₂O₃) or goethite (FeO(OH))

Smoky Quartz

Silicon Dioxide (SiO2)

Muscovite Mica

Muscovite / KAl2(AlSi3O10)(OH)2

River Pebble

Weathered Sedimentary Rock Fragment

Marble

Recrystallized Calcite (CaCO3) or Dolomite (CaMg(CO3)2)

Quartz-rich granite (likely leucocratic granite)

Granite, composed mainly of quartz and feldspar with minor dark minerals

Smooth gray pebbles

Unidentified rounded rock fragments; composition cannot be determined from the image

Clear Quartz (Druzy)

Crystalline Silicon Dioxide (SiO2)

Polished orbicular granite (likely larvikite or rapakivi-type granite)

Granite; primarily quartz, potassium feldspar, plagioclase, and biotite/hornblende

Concrete Fragment

Hardened Portland cement and mineral aggregate

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Quartz Geode

Crystalline Silicon Dioxide (SiO2)

Sedimentary Rock Fragments

Clastic Sedimentary Rock

Dalmatian Stone

Dalmatian Jasper (Aplitic Rock)

Orange Calcite

Calcium Carbonate (CaCO3)

Greenish rough stone, possibly serpentine or soapstone

Indeterminate from the image; possible serpentinite (serpentine-group minerals) or talc-rich soapstone

Weathered greenish rock fragment

Tentatively altered basalt or serpentinite; exact identification requires testing

Shale fragment

Shale (clay mineral rich sedimentary rock)

Basalt with Epidote Veins

Mafic Igneous Rock (Basalt)

Unknown Organic Object (likely a berry or fruit)

Not applicable; this is not a geological specimen. If it were a cranberry, its scientific name would be Vaccinium macrocarpon; if a cherry, it would be Prunus avium or Prunus cerasus.

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Conglomerate (rounded-pebble rock)

Lithified polymictic conglomerate; clasts cemented by a finer mineral matrix