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ESU Earth Science Department Presents

Minerals of Kansas

by

Susan Ward Aber
Emporia State University
Emporia, Kansas
USA

This webpage is designed to give a greater appreciation of minerals, which are the constituents of rocks and treasures of this Earth. Uses are discussed and physical properties common to minerals will be defined. The focus is on common minerals found in the state of Kansas. Although Kansas has no official state mineral, gem, rock, or fossil, a web resource listing other states resources may be visited at: official state rock, mineral, gem, and fossil. Specifically, this webpage was designed to help participants in 4-H programs, but I certainly invite anyone with a passion for minerals to read on and enjoy!

An Appreciation for Minerals     Mineral Use    Useful Physical Properties

General Kansas Mineral Locations     Kansas Mineral Identification    

References     Links

An Appreciation for Minerals

Pliny (A.D. 23-79) noted in his publication, Natural History, that minerals were non-renewable and extraction was not simply for the good of mankind, but for profit. A harvest of minerals reaps a one-time crop, so recycling and synthesis become especially important. Minerals valued as gemstones or specimens in 4-H collection boxes will survive! Gems are passed along through generations in museums and your 4-H specimens should be kept or recycled whenever possible.

Minerals are naturally occurring, homogeneous solids, with definite (but not fixed) chemical compositions, characteristic crystalline structures, and are usually of an inorganic origin. There are approximately 4,000 known mineral species that make up the Earth's crust. Of these specimens many are very rare and found in only one location. In Kansas, you may find over 20 specimens of minerals, although some will be abundant and others not so easy to find. Some of the minerals found in the state of Kansas include: sulfur, galena, sphalerite, pyrite, marcasite, hematite, limonite, goethite, magnetite, pyrolusite, halite, calcite, dolomite, barite, celestite, gypsum, mica, malachite, garnet, quartz, opal, and feldspar.

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Mineral Use

Minerals do play major roles in our everyday lives. Sulfur is used in making sulfuric acid and hydrogen sulfide, as well as in insecticides, soaps, textiles, paper, dyes, refining petroleum, and the vulcanization of rubber. Lead, extracted from galena, is no longer used in gasoline or paint, it is still needed for storage batteries, the shield around radioactive materials, and glass making. Sphalerite is an ore of zinc, which is used in medicines, paint, electric batteries, and as a wood preservative. Zinc is alloyed with copper to form brass and is used to galvanize iron and steel. Pyrite is used as a gemstone and as a source of sulfur for the manufacture of sulfuric acid. Marcasite is relatively rare and may be used as a source of sulfur. Magnetite, hematite, goethite, and limonite are all iron ores and used in the production of steel. Pyrolusite is an important ore of manganese although not abundant enough to be mined in Kansas. Manganese is used in making steel, and is a decolorizer for glass and a coloring material in bricks, pottery, and glass.

Halite (table salt) has been important throughout history. Halite continues to be a seasoning and preservative for food, although the greatest use is for the manufacture of hydrochloric acid. The most important use for calcite is in the manufacture of cement and mortar, although it is also used in optical instruments. Dolomite might be used as an ore of magnesium and possibly as building or ornamental stone. Barite is used in the drilling of oil and gas wells; barite is the "heavy mud" pumped into the hole to support the equipment and prevent blow outs caused by gas. Celestite is used for color in fireworks and in refining beet sugar. Gypsum is dehydrated, pulverized and shaped into sheets; after which it is rehydrated and with paper attached, forms the sheet rock or wallboard that make up the walls and ceilings of homes and businesses. The mica group of minerals include muscovite and biotite, which are used as insulating material and "isinglass" windows in furnaces and stoves. Ground muscovite gives the shiny luster to wallpaper and is the sparkle in some toothpaste marketed for children.

Malachite is a minor ore of copper. Malachite, garnet, opal, and quartz are gemstones. There are many varieties of gem quartz, which include: amethyst (purple), citrine (yellow to orange-red), rose quartz (pink), smoky (brown-black), tiger's eye (fibrous, chatoyant, and golden colored), aventurine (green), carnelian (orange), agate (many colors, usually banded), colorless (rock crystal), and onyx (black). Quartz is also used in mortar, concrete, glass, optical instruments, computer chips, radio and watches (oscillates to control frequencies), and as an abrasive. The feldspar group of minerals include albite, anorthite, and orthoclase. The principal use of feldspar is for porcelain and ceramics.

A wonderful site from the Canada Natural Resources displaying how minerals are essential to daily life is found at http://www.nrcan.gc.ca/mms/wealth/intro-e.htm.

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Physical Properties Useful in Identification

Physical properties may be seen, felt, tasted, or smelled. Helpful physical properties include: hardness, luster, color, streak, cleavage, fracture, and form or habit. Each mineral's unique properties will assist in identifying unknown specimens.

Whether a mineral breaks or not when dropped has nothing to do with hardness. The resistance a mineral has to scratching and abrasion is referred to as hardness. Harder minerals will scratches softer ones, minerals of equal hardness scratch each other. Hardness is measured on Mohs Hardness Scale (see Table 1-1.). This is a list of common minerals with arbitrary numbers assigned from 1 to 10, and some useful comparison items. If your fingernail scratches the mineral, the mineral's hardness is equal to or less than 2.5. If the unknown mineral does not scratch glass, then the mineral's hardness is less than 5.5.

Table 1-1. Mohs Hardness Scale
HardnessIndex Mineral Useful Comparison
1
Talc Candle Wax (1)
2
Gypsum Fingernail (2.5)
3
Calcite Penny (3)
4
Fluorite
5
Apatite Glass (5.5)
6
Orthoclase
7
Quartz Unglazed Tile (7)
8
Topaz
9
Corundum
10
Diamond

Luster refers to what the surface looks like. It is the quantity and quality of light that is reflected from the surface of a mineral and is divided into two categories: metallic and nonmetallic. Metallic luster is the look of metal and depending on the intensity of the reflection, can be referred to as bright or dull metallic. Nonmetallic luster can be divided into several categories that can be both seen and felt, such as: soapy, earthy, greasy, and vitreous (a glassy shine).

Color may be helpful, but it is not always reliable because many minerals are colorless or can occur in a variety of colors. Sulfur is always yellow and malachite is green, but quartz may be yellow, orange, brown, pink, reddish, purple, green, white, and colorless. One way to view the true color of the mineral is to rub it across an unglazed porcelain tile. The color that results is referred to as the mineral's streak, the color of a mineral in a powdered form. Streak is often most helpful in distinguishing the metallic minerals, such as hematite from magnetite or limonite.

Fracture or cleavage refers to the way a mineral reacts to stress, usually a blow from a hammer. If the break is very smooth, the mineral cleaves or separates along planes of atomic weakness. Cleavage results in a smooth, plane surface that reflects light back as if one rotated a mirror in the light. It can occur in one, two, three, four, or six different directions. If the mineral's atoms are connected or bonded so that the strength is uniform in all directions, the mineral will break in an irregular manner or fracture. Two common fractures are uneven (rough surface results) and conchoidal (smooth, curved, shell-like surface).

The form or habit of a mineral refers to the external shape. If a mineral has free space when it is growing, smooth faces and geometric shapes will result. Quartz commonly occurs with hexagonal cross-section, while halite is often a cubic form. A common form of calcite is scalenohedron, also called dog-tooth spar. Some common habit terms describing mineral shapes are stalagtitic (tapering cone), bladed (elongate, broad, flat), acicular (needle-like), equant (equidimensional), and globular (rounded masses, like a bunch of grapes).

There are other properties specific to some minerals that can also aid in identification. Magnetite is magnetic and will cling to a magnet. Halite will taste salty and sulfur and sphalerite will have a pungent smell after powdering a specimen on a streak plate. All carbonate minerals will "fizz" in a dilute hydrochloric acid (vinegar should work in most cases; dilute muriatic acid should also work).

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General Kansas Mineral Locations

Specific mineral sight locations are passed along from generation to generation and therefore this section is not specific. Sometimes the sight is best visited after storms, when new material is washed out of the sediment or rock outcrops. Some locations become depleted though from over collecting. Remember not to take more specimens than you need and leave specimens for future students and collectors. If you do not plan to keep your collection, please consider donating it back to the 4-H group leaders or to your local school science teachers for others to use and enjoy.

Several minerals are found in the former tri-state mining district in southeastern Kansas, which may include Cherokee, Chautauqua, Elk, and Sumner counties. Galena, mined in the tri-state area, is found in a cubic habit, whereas sphalerite may be found in cleavage masses or as tetrahedrons, three-sided pyramids with a flat base. Pyrite is also found in association with the lead and zinc deposits of galena and sphalerite, although it can occur with gypsum in the gray shales of western Kansas. It can be massive, cubic, octahedrons, or soccer ball-like pyritohedrons. It was produced as a byproduct of coal at West Mineral, southwest of Pittsburg, and used in making sulfuric acid (Tolsted & Swineford, 1971, p. 48). Marcasite, a secondary mineral formed from chalcopyrite, is found in a cockscomb habit in the lead and zinc mines of Cherokee county, as well as in balls or nodules in western Kansas. Calcite may be found as veins or crystals within limestones throughout the state. Larger calcite crystals are associated with the lead-zinc mines of southeastern Kansas and in some limestone quarries in Franklin County. Vein calcite is found in the rare sedimentary structures called septarian concretions in Wallace County. Dolomite crystals occur in Cherokee County, but have also been reported from Franklin County and other locales.

Minute amounts of sulfur may be found around coal dumps, in an earthy massive habit or as acicular or needle-like crystals. Hematite nodules and earthy massive varieties may be found in the sandstones of Woodson, Ottawa, Russell, and Lincoln counties. Limonite and/or goethite, yellowish brown minerals, are often found in association with the hematite as nodules in sandstones, or as octahedrons, which are pseudomorphs or replacements of the original pyrite. Magnetite can be found in river gravels and sometimes as massive pieces in the glacial drift of northeastern Kansas. Pyrolusite is found in a dendritic habit, as if "painted" onto limestones and the moss agate and/or opals of Wallace, Trego, and Logan counties; it can also occur as a dark stain on common chert. Halite does not outcrop at the surface but is actively mined in Hutchinson. Minute amounts of malachite are found Sumner County, in Permian shales and limestones.

Barite may be found as a bright white or clear, flat tabular or massive habits. It may be found as the cement of grains in a concretion commonly referred to as a "rose" or "walnut." These have been reported in Saline County, and earthy or granular forms of barite may be found in Logan, Wallace, Brown Anderson, Franklin, and Chase counties ( Tolsted & Swineford, 1971, p. 48). Celestite may resemble barite and occur near to it. It may also be found as pink fibrous habit, or as veins in nodules or in geodes, in Chase and Brown counties. Gypsum crystals are found in the Cretaceous gray shales of western Kansas and as vein fillings or massive varieties Clay, Saline, Dickinson, Marion, Harvey, Sedgwick, and Comanche counties. Gypsum has been mined in Marshal and Barber counties. Small garnets are found in the Riley County igneous intrusive rock termed the Stockdale pipe. Tiny flakes of muscovite, phlogopite, and vermiculite micas are found in the igneous intrusions of Riley and Woodson counties, as well as in sandstones and siltstones around the state. Quartz, a common mineral, may be found in almost every county although crystals are somewhat rare. Crystals of quartz have been found in Harvey, Wyandotte, Chase, and Woodson counties. A cryptocrystalline variety of quartz, known as flint, chert, jasper, or agate, may be found in several regions in the state including the glaciated northeastern portion and southeastern mining district.

Although it is not a mineral, amber, a hardened petrified resin, was found in Kansas in Cretaceous lignite beds along the banks of the Smoky Hill River, Ellsworth County. This locality is under Kanopolis reservoir now and possibly may be found washing up on the shore. The amber was discovered by George Jelinek from Ellsworth and was named jelinite in his honor (Tolsted & Swineford, 1971, p. 39).

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Kansas Mineral Identification

If you already have or will be collecting minerals, Table 1-3 presents some facts about some of the minerals you may encounter in Kansas.

Table 1-3. Facts regarding Kansas minerals
Classification Mineral Hardness Distinguishing Characteristics
Oxide Pyrolusite <2.5 black encrustation or branching pattern painted on the rock
Native Element Sulfur <2.5 yellow color, waxy/earthy luster, & streak stinks
Halide Halite <2.5 colorless, dull or vitreous luster, & cubic cleavage
Silicate Muscovite <2.5 flexible and elastic, one-directional cleavage sheets, light in color
Sulfate Gypsum <2.5 colorless, cleavage faces prominent, flexible but not elastic
Sulfide Galena <2.5 shiny, gray metallic, very heavy for size, cubic cleavage
Sulfide Sphalerite >2.5, <5.5 cleavage prominent, smelly pale yellow streak, golden brown in color
Sulfate Celestite >2.5, <5.5 resembles barite but lower specific gravity or heft; peachy color
Sulfate Barite >2.5, <5.5 distinctive habit, heavy specific gravity, red or yellow "rose," white or clear crystals
Carbonate Calcite >2.5, <5.5 light color, 3 direction rhomb-shaped cleavage or dogtooth shape
Carbonate Malachite >2.5, <5.5 green encrustations on a rock, will streak green
Carbonate Dolomite >2.5, <5.5 pink saddle-shaped crystals when freshly exposed; yellowish crystals after weathered
Oxide Limonite or Goethite >5.5 rusty-earthy look, characteristic yellow- brown streak
Oxide Magnetite >5.5 dark color, metallic look & heavy feel, dark streak
Oxide Hematite >5.5 dark color varies from reddish to black, red-brown streak
Silicate Orthoclase >5.5 pink/peach color, cleavage prominent, vitreous
Sulfide Pyrite and Marcasite >5.5 brassy metallic, heavy to feel, dark streak - marcasite will be in a cockscomb habit
Silicate Garnet >5.5 dark color, no cleavage, tiny roughly spherical or dodecahedral in shape
Silicate Opal >5.5 milky color, low specific gravity or heft, translucent with a waxy luster
Silicate Quartz >5.5 many colors, no cleavage, massive or hexagonal crystals possible

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References to Aid in Identification and Uses of Minerals

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Helpful Web Links

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Thanks for visiting! This page originates from the Earth Science department at Emporia State University. The curriculum is © by the author, and for more information contact S. W. Aber, e-mail: saber@emporia.edu Thanks for visiting! Created: 7 February, 2000. Last update: 26 February, 2008.

copyright 2000-2008 © Susan Ward Aber. All rights reserved.