Organic Crystal (Mineraloid)

Chert / Flint

Chert (varietal name for microcrystalline quartz). Chemical formula: SiO₂

Sea Glass (specifically Frosted White)

Amorphous Silica (substance: Sodium-calcium silicate glass)

Pyrite

Pyrite (Iron Disulfide), FeS2

Sea Glass (Frosted Glass)

Amorphous Silica (SiO2) with various additives

Chert / Flint

Chert (varieties include Flint)

Amber (Copal)

Organic gemstone, fossilized tree resin (often immature amber or copal)

Green Sea Glass

Amorphous Silica (man-made glass), SiO2 + additive metal oxides

Conglomerate

Conglomerate

Shale or Mudstone (Based on appearance)

Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)

Cherry Creek Jasper (also known as Red Creek Jasper or Cherry Creek Agate)

Jasper, microcrystalline quartz (SiO₂)

Mookaite Jasper

Siliceous (chert) sedimentary rock, a form of Jasper

Banded Chert

Chert (a microcrystalline variety of quartz, SiO2 with minor impurities)

Asphalt

Asphalt concrete (engineered material, not a naturally occurring rock/mineral in this form)

Pyrite

Iron Pyrite (FeS2)

Chert (varietal known as Jasper or Flint)

Silicon Dioxide (SiO2)

Coal (most likely Bituminous or Anthracite)

Bituminous Coal (Grade of Coal), Anthracite (Grade of Coal)

Coal (specifically Bituminous or Anthracite)

Organic sedimentary rock; primarily Carbon (C) with varying H, S, O, N

Petrified Wood

Silicified wood, primarily composed of Quartz (SiO2)

Pyrite

Pyrite (Iron Disulfide), FeS2

Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)

Chert (microcrystalline quartz)

Shale or Argillite

Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)

Shale

Shale (clastic sedimentary rock)

Travertine (used in construction, not a 'specimen' in situ)

Travertine

Shale or Argillite

Shale (sedimentary) / Argillite (metamorphic)

Opalite (a synthetic glass, often confused with Opal)

Silicon dioxide glass (SiO2nH2O, for natural opal)

Petrified Wood

Silicified wood (Quartz/Chalcedony)

Coral (Precious Coral)

Corallium rubrum (Red Coral), Paracorallium japonicum (Momo Coral), Pleurocorallium elatius (Sardinian Coral), various other species within the Corallidae family. Chemically, it's primarily Calcium Carbonate (CaCO 3 ).

Pyrite

Pyrite (Iron sulfide, FeS₂)

Baltic Amber (Butterscotch or Egg Yolk Variety)

Fossilized Tree Resin (Succinite); Approximate formula: C10H16O

Chalcedony Geode

Chalcedony (SiO2) within a geode structure

Baroque Pearl (and potentially a small Sapphire/Blue Topaz)

Pearl: Calcium Carbonate (aragonite or calcite) with conchiolin. Sapphire: Aluminum Oxide (Al2O3). Blue Topaz: Al2SiO4(F,OH)2.

Amber

Fossilized tree resin (not a true mineral as it is organic and amorphous); Chemical formula is highly variable, but often approximated as C10H16O.

Anthracite Coal

Anthracite (Carbon-based organic sedimentary rock exposed to metamorphic heat/pressure; Chemical composition is approximately 86%–98% Carbon)

Baltic Amber (Butterscotch or Egg Yolk Variety)

Succinite (C10H16O)

Ambergris (Sea Wax)

Physeter macrocephalus fecalith

Shale (possibly)

Shale (fine-grained clastic sedimentary rock)

Red Coral

Corallium rubrum (for precious red coral), although other species like Corallium japonicum and Paracorallium are also used.

Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate)

N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)

Pegmatite (Granitic)

Granitic Pegmatite containing Quartz, Feldspar, and Tourmaline (Schorl)

Gabbro

Gabbro (composed mainly of calcium-rich plagioclase feldspar and pyroxene)

Granite

Granite (composed primarily of Quartz SiO2, Potassium Feldspar KAlSi3O8, and Plagioclase)

Prasiolite and Quartz Crystal Cluster

Quartz (SiO2); Prasiolite is a variety of Quartz