Sedimentary Rock (Possibly Composed Of Various Minerals)

Quartz

Quartz (SiO₂)

Pyrite on Quartz

Iron Sulfide (FeS2) on Silicon Dioxide (SiO2)

Likely porphyritic igneous rock (possibly granite or rhyolite)

Quartz–feldspar–mica aggregate; exact identification requires a fresh surface and tests

Blue copper-mineral rock, likely chrysocolla-bearing copper ore

Chrysocolla (hydrated copper aluminosilicate), possibly with malachite, quartz, or host rock

Pyrite in Quartz

Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)

Fossilized Brachiopod

Brachiopoda (Phylum)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) vein cutting through host rock

Limestone

Calcareous sedimentary rock (CaCO3)

Carnelian

Carnelian (a variety of Chalcedony, SiO2)

Granite Pebble

Granite (composed primarily of Quartz, Feldspar, and Mica/Amphibole)

Potassium Feldspar (Orthoclase)

KAlSi3O8 (Potassium Aluminum Silicate)

Conglomerate

Conglomerate (clastic sedimentary rock)

Celestine (or Celestite)

Strontium sulfate (SrSO4)

Chert / Flint

Cryptocrystalline quartz (SiO2)

Basalt

Basalt

Mixed pebble collection, including likely flint, quartzite, and fossil material

Varied silicate rocks; visible specimen may include chert (microcrystalline SiO₂), quartzite, and a possible fossil

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Granitic Pegmatite (with Smoky Quartz and Mica)

Granitic Pegmatite (composed of SiO2, KAl2(AlSi3O10)(OH)2, and (K,Na)(AlSi3O8))

Pyrite

Pyrite (Iron Disulfide), FeS2

Shale (or Mudstone)

Clay mineral aggregate / Fine-grained siliciclastic sedimentary rock

Pale blue-gray quartz-rich pebble (tentative)

Quartz, SiO₂, possibly chalcedony or a weathered metamorphic fragment

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Pink Dyed Agate

Silicon Dioxide (SiO2) with artificial pigment

Iron-rich vesicular rock, possibly slag or weathered basalt

Identification uncertain; likely ferruginous basalt/ironstone, with possible anthropogenic iron slag

Orange Calcite

Calcium Carbonate (CaCO3)

Granite

Phaneritic Felsic Igneous Rock

Weathered quartz-rich metamorphic rock, possibly quartzite

Quartzite; predominantly quartz (SiO₂), with minor feldspar, mica, and iron-oxide staining

Chalcedony Pebble

Cryptocrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Red Sandstone Pebble

Quartzose Sandstone

Quartz Pebble

Silicon Dioxide (SiO2)

Hematite Nodule

Hematite (Fe2O3)

Banded Chert in Matrix

Microcrystalline Quartz (SiO2)

Milky quartz (likely vein quartz)

Quartz, silicon dioxide (SiO₂)

Limestone

Calcium Carbonate (CaCO3)

Rhinestone (or glass crystal)

Silicon dioxide (if glass) / Various

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Polished jasper (likely brecciated or iron-rich jasper)

Microcrystalline quartz (SiO₂), colored by iron oxides/hydroxides and possibly sulfide minerals

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals like Antigorite, Lizardite, and Chrysotile)

Conglomerate

Clastic Sedimentary Rock

Iron-rich sulfide ore, likely pyrite-bearing gossan

Pyrite (FeS₂), possibly mixed with iron oxides/hydroxides and other sulfides

Chert (varietal Chalcedony or Flint)

Silicon dioxide (SiO2) - Microcrystalline Quartz