Missouri Rocks and Minerals
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Minerals
| Picture | Name | Color | Luster | Mohs | Tenacity | Specific Gravity | Crystal Habit | Other Characteristics |
|---|---|---|---|---|---|---|---|---|
 | Barite | Colorless, white, and light shades of blue, yellow, red; transparent to translucent; commonly stained superficially with red iron oxide | Vitreous, sometimes pearly in part | 3-3.5 | Brittle | 4.5 | Commonly in divergent groups of tabular orthorhombic crystals that are called crested barite or barite roses; less commonly in stouter prismatic (pseudo-cubic) orthorhombic crystals | Nontoxic and low solubility |
 | Calcite | Typically colorless or white - may have shades of various colors | Vitreous to pearly on cleavage surfaces | 3 | Brittle | 2.71 | Crystalline, granular, stalactitic, concretionary, massive, rhombohedral | May fluoresce red, blue, yellow, and other colors under either SW and LW UV; phosphorescent Soluble in dilute acids |
 | Galena | Lead gray and silvery | Metallic on cleavage planes | 2.5-2.75 | Brittle | 7.2–7.6 | Cubes and octahedra, blocky, tabular and sometimes skeletal crystals | Natural semiconductor |
 | Limonite | Various shades of brown and yellow | Earthy | 4-5.5 | Soft | 2.9-4.3 | Fine grained aggregate, powdery coating | No cleavage |
 | Magnetite | Black, gray with brownish tint in reflected sun | Metallic | 5.5-6.5 | Brittle | 5.17–5.18 | Octahedral, fine granular to massive | Dissolves slowly in hydrochloric acid |
 | Marcasite | Pale brass-yellow, tin-white on fresh exposures | Metallic | 6-6.5 | Brittle | 4.875 | Typically tabular, curved faces common, stalactitic, reniform | |
 | Missouri Lace Agate | Banded | Waxy | 6.5-7 | 2.58-2.64 | Cryptocrystalline silica | Translucent | |
 | Pyrite | Pale brass-yellow reflective; tarnishes darker and iridescent | Metallic, glistening | 6-6.5 | Brittle | 4.9-5.10 | Pale brass-yellow reflective; tarnishes darker and iridescent | Insoluble in water |
 | Quartz | Colorless through various colors to black | Vitreous – waxy to dull when massive | 7 | Brittle | 2.65 | 6-sided prism ending in 6-sided pyramid (typical), drusy, fine-grained to microcrystalline, massive | Insoluble at standard temp and pressure Lattice: hexagonal, Piezoelectric, may be triboluminescent, chiral |
Igneous Rocks
| Picture | Name | Description | Composition |
|---|---|---|---|
 | Granite | Due to differences in mineralogical composition and differences in cooling rates, the colors and textures of the granites are quite different | Felsic Potassium feldspar Plagioclase feldspar Quartz |
 | Rhyolite | Referred to by stone producers as a “traprock,” Missouri rhyolite varies in color from light gray through pink and red to dark purplish-red Sometimes it has a distinct banded pattern | Felsic Igneous quartz Alkali feldspar |
Metamorphic Rocks
Sedimentary Rocks
| Picture | Name | Description | Composition |
|---|---|---|---|
 | Chert | White, tan or light gray Red, brown, reddish-brown and yellowish-brown varieties are called jasper Black and dark gray specimens are known as flint Mottled and pink types are called Mozarkite Some banded varieties have found a home in the agate family | Quartz Feldspar |
 | Coal | Black Leaves residue | Carbon |
 | Conglomerate | Consists of pieces known as clasts of pre-existing rocks, pebbles, cobble or boulders that are naturally cemented together in a finegrained matrix of sand, silt, calcium carbonate, iron oxide, silica or clay | |
 | Fireclay | Buff, yellow, red, green or brown Good, useable fireclay is usually white, cream-colored, gray, or almost black | Aluminum oxide |
 | Limestone | Typically white, gray or tan; can also occur in shades of yellow, green, blue, brown, pink. red, or black | Calcite Dolomite |
 | Mozarkite | Mottled pink and white version of chert | Silica Chalcedony |
Fossils
| Picture | Name | Description |
|---|---|---|
 | Bivalves | Shells of bivalves are composed of two separate valves, typically about the same size. They often nearly mirror one another. The valves are bound together with a bendable ligament (band of tissue) along a hinge line on the dorsal (back) side of the shell |
 | Blastoids | Blastoids are related closely to another group of similar-looking stemmed echinoderms called crinoids. Blastoids differ from crinoids in having a more highly developed five-sided (pentamerous) symmetry and specialized anatomical features that are lacking in crinoids Also, blastoids tended to be smaller in size and shorter stemmed |
 | Brachiopods | The outer surface of brachiopod shells can be smooth, ribbed, ridged or spiny The inner surface is mostly smooth with ridges, muscle scars and other markings that are used in classification and identification |
 | Conulariid Jellyfish | Conulariid periderms have a four-sided pyramid shape that typically is elongated from apex to opposite end (aperture) |
 | Crinoid | Most often, crinoid fossils are found in limestone as dismembered pieces with their individual hard parts preserved |
 | Gastropods | Shells are made of calcium carbonate in the form of the minerals aragonite or calcite or both Shells can be uncoiled or coiled. Uncoiled shells are cap-shaped to horn-shaped Coiled shells wrap around themselves spirally as they grow |
 | Nautiloid | Rigid, one-piece, external, calcium carbonate shells |
 | Starfish | Fossils of whole starfish are rare |
 | Regular Echinoids | Individual spines and individual ossicles are the typical finds while fossils of whole echinoids are rare |
 | Trilobite | Three-lobed construction of their bodies, with a central (axial) lobe flanked by two side (pleural) lobes. Their bodies consisted of a head (cephalon) with two compound eyes similar to present-day insects, a body (thorax) and a tail (pygidium) |
