2.5" x 1.25"Purchase Price: $4.00Amethyst is a purple variety of quartz (SiO2) and owes its color to irradiation, iron impurities, and the presence of trace elements. The name in ancient Greek means "not intoxicated". Amethyst is the birthstone for February.
1.5" x 1.25"Purchase Price: UnknownAmmonites are extinct marine invertebrates. They first appeared in the Late Silurian to Early Devonian period (around 400 million years ago) and became extinct at the end of the Cretaceous period (65 million years ago).
2.5" x 2.25"Purchase Price: $10.00Perisphinctes is an extinct genus of ammonite cephalopod also known as a larger version of a snail. They lived during the Jurassic Period (200-146 million years ago) and serve as an index fossil for that time period.
4" x 4"Purchase Price: NAAndesite is an extrusive igneous, volcanic rock of intermediate composition (52-63% SiO2). This sample is porphyritic, which means that at least one group of crystals is obviously larger than another group.
1.5" x 1.25" x 1"Purchase Price: $2.95Aragonite is a crystal form of calcium carbonate (CaCO3). It will change to calcite at 380-470°C. Its crystal shape is an orthorhombic system with acicular crystals. Repeated twinning results in pseudo-hexagonal forms.
1.5" x 1" x 1"Purchase Price: $10.00Bismuth is a brittle metal with a white, silver-pink hue. The bright colors are from an iridescent oxide tarnish. Bismuth is naturally diamagnetic, meaning it repels magnets.
4" x 2.5" x 2"Purchase Price: $8.00Silicon carbide (SiC), also known as carborundum. Grains of silicon carbide can be bonded together by sintering to form very hard ceramics which are widely used in applications requiring high endurance, such as car brakes, car clutches and ceramic plates in bulletproof vests.
4" x 2.5" x 2"Purchase Price: NAThese commonly-seen structures form principally in subaerial cave settings by mineral precipitation as water seeps by capillary action from cave walls or from dripstone or flowstone.
1.75" x 1.25" x 1"Purchase Price: $0.75Chalcopyrite is a copper iron sulfide mineral (CuFeS2). From Greek chalkos "copper", and pyrites "fire". The irridescent blues, greens, yellows, and purples are tarnish.
1.75" x 1.25" x 1"Purchase Price: $0.75Chalcopyrite is a copper iron sulfide mineral (CuFeS2). From Greek chalkos "copper", and pyrites "fire". The irridescent blues, greens, yellows, and purples are tarnish.
4" x 3"Purchase Price: $8.00Citrine is a yellow to golden-brown variety of quartz, with a hardness of 7 on Moh's Scale.
Citrine's golden, amber color is caused by heat interacting with Amethyst in the depths of the earth. At times, Citrine is created by the artificial heating of Amethyst, which changes from purple to gold at 878°F.
2.25" x 1.5"Purchase Price: NACoal is an organic sedimentary rock that forms mainly from plant debris. Coal is combustible and is often mined for use as a fuel.
3.5" x 2" x 1.5"Purchase Price: NAConglomerate is a clastic sedimentary rock that contains large (greater than 2 mm) rounded particles. The space between the pebbles is generally filled with smaller particles and/or a chemical cement that binds the rock together.
7" x 4" x 3"Purchase Price: NACoquina is a sedimentary rock that is composed largely of the transported, abraded, and mechanically sorted fragments of either mollusks, trilobites, brachiopods, or other invertebrates.
0.75" x 0.5"Purchase Price: UnknownJasper, an impure variety of silica, is an opaque rock of virtually any color stemming from the mineral content of the original sediments or ash. Patterns arise during the consolidation process.
0.75" x 0.5" x 0.5"Purchase Price: $0.35Fluorite is a halide mineral composed of calcium fluoride, CaF2. Many samples of fluorite exhibit flourescence under ultraviolet light, a property that takes its name from fluorite. It has a defining Mohs hardness of 4.
0.75" x 0.5" x 0.5"Purchase Price: $0.35Fluorite is a halide mineral composed of calcium fluoride, CaF2. Many samples of fluorite exhibit flourescence under ultraviolet light, a property that takes its name from fluorite. It has a defining Mohs hardness of 4.
1" x 1" x 1"Purchase Price: $11.97Garnet species are found in many colors and generally fit into one of 6 species. The general chemical formula is X3Y2(SiO4)3. Garnets have a cubic crystal system, and this specimen is a rhombic dodecahedron. Notice that each of the 12 faces is a rhombus and that garnet has a square cross section in one direction and a hexagonal cross section in the other directions.
2.5" x 2"Purchase Price: NAAfter rock around the cavity hardens, dissolved silicates and/or carbonates are deposited on the inside surface. Over time, this slow feed of mineral constituents from groundwater or hydrothermal solutions allows crystals to form inside the hollow chamber.
4" x 2.5"Purchase Price: $4.00After rock around the cavity hardens, dissolved silicates and/or carbonates are deposited on the inside surface. Over time, this slow feed of mineral constituents from groundwater or hydrothermal solutions allows crystals to form inside the hollow chamber.
Purchase Price: NAGneiss is a common and widely distributed foliated metamorphic rock that has a banded appearance and is made up of granular mineral grains. It is formed at great depths below the earth's surface from formations that were originally either igneous or sedimentary.
3" x 2.25"Purchase Price: NAGypsum (CaSO4·2H2O) is a very soft sulfate mineral. It is the main constituent in gypsum board (sheetrock) and is also used in fertilizer. The word gypsum is derived from the Greek gypsos, "chalk" or "plaster". It has a defining Mohs hardness of 2.
1" x 1" x 1"Purchase Price: $0.50The rosette crystal habit tends to occur when the crystals form in arid sandy conditions, such as the evaporation of a shallow salt basin.
9" x 5" x 3"Purchase Price: $7.50The rosette crystal habit tends to occur when the crystals form in arid sandy conditions, such as the evaporation of a shallow salt basin.
1" x 1" x 1"Purchase Price: UnknownSatin spar is a crystalline mineral variety of gypsum. The crystals are most often silky, fibrous, and translucent (pearly, milky).
5" x 2"Purchase Price: UnknownSatin spar is a crystalline mineral variety of gypsum. The crystals are most often silky, fibrous, and translucent (pearly, milky).
8" x 3.5" x 0.5"Purchase Price: $3.00Selenite is a crystalline mineral variety of gypsum (CaSO4·2H2O). The crystals form in mica-like sheets that sometimes appear like columns.
2" x 1.5" x 1"Purchase Price: NAPyrite is an iron sulfide with the formula FeS2. The name pyrite is from the Greek word meaning "fire". Pyrite creates sparks when struck against steel. It is nicknamed fool's gold because of its resemblance to gold.
4" x 2.5"Purchase Price: $14.95Pyrite is an iron sulfide with the formula FeS2. The name pyrite is from the Greek word meaning "fire". Pyrite creates sparks when struck against steel. It is nicknamed fool's gold because of its resemblance to gold.
5.25" x 4"Purchase Price: $18.47A 50 million year old, Eocene-Era fossil fish. It is the state fossil of Wyoming and the most commonly excavated fossil fish in the world.
1.75" x 1.5" x 1.5"Purchase Price: $2.95Lepidolite (KLi2Al(Al,Si)3O10(F,OH)2) is a lilac-gray member of the mica group. Named after the greek lepidos meaning "scale", in reference to the scaly flakes. It is a major source of lithium, the world's lightest metal, which is used in batteries and other applications.
Purchase Price: NALimestone is a rock that is composed primarily of calcium carbonate. It can form organically from the accumulation of shell, coral, algal and fecal debris. It can also form from the precipitation of calcium carbonate from lake or ocean water.
Purchase Price: NAMilky quartz may be the most common variety of crystalline quartz and can be found almost anywhere. The white color may be caused by minute fluid inclusions of gas, liquid, or both, trapped during the crystal formation. The cloudiness caused by the inclusions effectively bars its use in most optical and quality gemstone applications. Milky quartz is widely used as a decorative landscaping material by gardeners.
1" x 1" x 1"Purchase Price: NAThe iron oxide concretions consist of sandstone cemented together by hematite (Fe2O3), and goethite (FeOOH). They were created by the precipitation of iron, which was dissolved in groundwater.
2" x 1.5" x 0.25"Purchase Price: UnknownMuscovite is the most common mica. It has a highly-perfect basal cleavage yielding remarkably-thin sheets which are often highly elastic.
2" x 1.5" x 1"Purchase Price: NAPure obsidian is usually dark in appearance, though the color varies depending on the presence of impurities. Iron and magnesium typically give the obsidian a dark brown to black color.
1.5" x 1.25" x 0.75"Purchase Price: UnknownCalcite is the most stable polymorph of calcium carbonate (CaCO3). It has a defining Mohs hardness of 3. Calcite crystals are rhombohedral. They display an optical property called birefringence, in which light is polarized and split into two paths. This results in a double image when viewed through the crystal.
8" x 6"Purchase Price: $7.00Orthoceras fossils are dated back to the Silurian Age 400 + million years ago and are the earliest recognizable animals. They are ancestors to the modern day squid. The name means straight horn.
3" x 1.5"Purchase Price: $1.00Geologic age is Middle Pennsylvanian 299-318 million years old. Francis Creek Shale. Plants bearing these leaves went extinct around the beginning of the Permian period.
6" x 4" x 3"Purchase Price: NAThe petrifaction process occurs underground, when wood becomes buried under sediment and is initially preserved due to a lack of oxygen which inhibits aerobic decomposition. Mineral-laden water flowing through the sediment deposits minerals in the plant's cells; as the plant's lignin and cellulose decay, a stone mold forms in its place.
5" x 3" x 1"Purchase Price: NAAge: Precambrian to recent. These burrows, which may reach a width of 5/8", were made by wormlike animals that ate sediment as they burrowed. Planolites is one of the oldest of all fossils.
3" x 2"Purchase Price: NAAge: Precambrian to recent. These burrows, which may reach a width of 5/8", were made by wormlike animals that ate sediment as they burrowed. Planolites is one of the oldest of all fossils.
3" x 2" x 2"Purchase Price: NAPumice is a textural term for a volcanic rock that is a solidified frothy lava typically created when super-heated, highly pressurized rock is violently ejected from a volcano.
2" x 2" x 2"Purchase Price: NAQuartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. It has a defining Mohs hardness of 7.
2" x 0.75" x 0.75"Purchase Price: UnknownQuartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. It has a defining Mohs hardness of 7.
2" x 2" x 2"Purchase Price: UnknownQuartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. It has a defining Mohs hardness of 7.
4" x 3" x 1"Purchase Price: $5.00Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. It has a defining Mohs hardness of 7.
2.5" x 1.5" x 1.5"Purchase Price: NAQuartz monzonite is an intrusive igneous rock. Granite contains more than 20% quartz while quartz monzonite contains only 5-20%. The mineral crystals are quartz (clear), feldspar (white), and biotite (black).
2.5" x 1.5" x 0.5"Purchase Price: NAQuartzite is a non-foliated metamorphic rock that is produced by the metamorphism of sandstone. It is composed primarily of quartz.
3" x 2" x 0.5"Purchase Price: NATuff is a type of rock consisting of consolidated volcanic ash. Each layer represents a separate eruption that covered everything around with hot ash, dust, and small bits of rock and molten lava.
4" x 2" x 2"Purchase Price: $4.00Rose quartz is a type of quartz that exhibits a pale pink to rose red hue. The color is usually due to trace amounts of titanium, iron, or manganese in the massive material.
4" x 4" x 0.5"Purchase Price: NASandstone is a clastic sedimentary rock made up mainly of sand-size (1/16 to 2 mm) weathering debris. Environments where large amounts of sand can accumulate include beaches, deserts, flood plains, and deltas.
6" x 4" x 0.5"Purchase Price: NASchists constitute a group of medium-grade (between phyllite and gneiss) metamorphic rocks with more than 50% platy and elongated minerals such as micas, chlorite, graphite, and others. Most schists have been derived from clays and muds.
5" x 3.5" x 2"Purchase Price: NAScoria is a volcanic rock containing many holes or vesicles, which form when gases that were dissolved in the magma come out of solution as it erupts. Scoria is most often dark in color and basaltic or andesitic in composition.
3" x 3"Purchase Price: $8.00Septarian nodules are concretions containing angular cavities or cracks. Latin word septum means "partition". The yellow centers are calcite, the brown lines are aragonite, and the outer grey rock is limestone. Formed when bentonite clay balls dried and cracked then the ocean returned and deposited calcite in the cracks.
4" x 3" x 0.25"Purchase Price: NAShale is a clastic sedimentary rock that is made up of clay-size (less than 1/256 mm) weathering debris. It typically breaks into thin flat pieces.
Purchase Price: NASiltstone is a clastic sedimentary rock that forms from silt-size (between 1/256 and 1/16 mm) weathering debris. Stratification is likely to be obscure and tends to weather at oblique angles unrelated to bedding.
Purchase Price: NASlate is a foliated metamorphic rock that is formed through the metamorphism of shale. It is a low grade metamorphic rock that splits into thin pieces. Slate is frequently gray in color.
2" x 1" x 1"Purchase Price: UnknownAgate is a microcrystalline variety of silica, cheifly chalcedony, with multi-colored curved or angular banding. Snakeskin agate is named because of the unusual surface pattern.
2" x 1.5" x 1"Purchase Price: NAObsidian consists mainly of SiO2. In some stones, the inclusion of small, white, radially clustered crystals of cristobalite in the black glass produce a blotchy or snowflake pattern (snowflake obsidian).
6" x 2" x 2"Purchase Price: $4.00Soapstone is a metamorphic rock, a talc-schist. It is largely composed of the mineral talc, which has a Mohs hardness of 1. It has been a medium of carving for thousands of years.
14" x 3"Purchase Price: $0.25Water containing carbon dioxide dissolves calcium carbonate from limestone, forming a calcium bicarbonate solution in underground caverns. This solution travels through the rock until it comes into contact with air. A chemical reaction takes place, and particles of calcium carbonate are deposited.
6" x 6" x 3"Purchase Price: $0.75Sulfur is a chemical element with symbol S and atomic number 16. Elemental sulfur is a bright yellow. Octasulfur (S8) is a soft yellow solid with only a faint odor, similar to matches. Sulfur is very flamable and burns with a blue flame.
0.25" x 0.25" x 0.25"Purchase Price: NASunstone is a transparent, yellowish labradorite (a plagioclase feldspar mineral). It is the official gemstone of Oregon.
2" x 2"Purchase Price: UnknownThunderegg is not synonymous with either geode or agate. A geode is a simple term for a rock with a hollow in it, often with crystal growth. A thunderegg on the other hand is a specific geological structure. The egg is composed of two distinct parts, the matrix or rind (the outer part) and the agate center which is usually called the lens or the window.
0.25" x 0.25"Purchase Price: NATopaz is a silicate mineral of aluminum and fluorine with the chemical formula Al2SiO4. Pure topaz is colorless and transparent, but it is usually tinted by impurities. Orange topaz is the birthstone of November and the state gemstone of Utah. It has a defining Mohs hardness of 8.
3" x 2" x 2"Purchase Price: $6.00Tourmaline is a semi-precious stone that is most often black but can also be brown, violet, green, or pink. It is a crystal boron silicate mineral compounded with elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. It is 1-7.5 on Mohs hardness scale.
3" x 2"Purchase Price: $2.00Geologic age is Ordovician, 488-443 million years old. This trilobite grew to a length of 2.5 inches and fed on small edible particles in the water.
8" x 6"Purchase Price: $25.00Cambropallas Telesto trilobites are known to have inhabited the earth during the Cambrian Period 500 million years ago and are among some of the earliest trilobites to appear in the fossil record. They have well developed genal spines and clearly segmented glabella.
2" x 2"Purchase Price: $6.80Willemite is a zinc silicate mineral (Zn2SiO4). It is highly fluorescent (green) under shortwave ultraviolet light. Calcite (CaCO3) glows red.
