Gypsum – More than just a cave!

By Duane Del Vecchio

Central Oklahoma Grotto

Orginal Writing January 2006 - Updated January 2008

Ahhh… Gyp… If you’ve ever caved in western Oklahoma, you know the stuff.  It makes nice passageways for water to go from one side of a hill to another and in the process can make some pretty spectacular caves!  We even have the longest gyp cave in the USA! But there is so much more to Gyp!  So sit back and learn a little about our Oklahoma resource.

What is it?

The word Gypsum comes from the Arabic word (jips) meaning plaster and then the Greeks (gypsos) which means chalk.  Gyp (which is short for Gypsum) is found on all human occupied continents of the world (which means I’m not sure about Antarctica).  It is formed when “the great shallow sea”, which everyone always says used to lay over his or her section of land, evaporates off and leaves the mineral usually embedded in the sedimentary layers and normally in thick beds. The chemical formula for Gypsum, (hydrated calcium sulphate), is CaSO4.2H2O and pure gyp is CaSO4

Types of Gyp

The four most common types of gypsum are Rock Gypsum, Selenite, Alabaster, and Satin Spar.  Rock Gyp is the white rock that is mined and used for industrial uses (see below in article).  Selenite (from the greek meaning Moon Rock) has some of its past in the Soothsayers and fortunetellers as it was used to access the past and future life of an individual and is associated with the Astrological formation Taurus.  In the Mystical & Healing beliefs, it is the most used of the gyp types.  It is used in communications with angels, a calming and soothing stone, it enhances the energy of other crystals, it creates harmony, can be used to test honesty, bring inner peace and meditation, love, increase psychic abilities and intuition, enhance spiritual development and find truth.  It used to be used for windows before glass was created.  Alabaster and Satin Spar are forms of gypsum that are of a fibrous variety and thus were in the early times (and still are) used for carvings and sculptures.  Satin Spar is also used for bead making and when polished makes a soft satiny stone used in jewelry.

Gypsum in Oklahoma is primarily found in large quantities in the western parts of Oklahoma mostly in Blaine, Caddo, Comanche, Jackson and Major Counties. Oklahoma is the largest gypsum producing state in the nation with over 15,700,000 metric tons mined at the value of approximately $108,000,000 annually. (2002 figures*1)   In industry, there are three kinds of gypsum used when using the Rock Gyp:  Uncalcined, Calcined, and Anhydrite.  Uncalcined is raw gypsum with water still part of it.  Calcined is where 75% of the water has been removed.  Anhydrite is gypsum with all of the water removed.

Uses of Gyp

Uncalcined Gypsum is used in drilling muds for the petroleum industry, blackboard chalk, a filler in paper and cotton, in paints, an additive to cement for controlling the setting time, it is the chalk used on baseball fields, decorative rock for the garden, and glassmaking. It is used in the farming industry as a fertilizer, a salt buster, and a clay buster.  Gypsum treated soils hold more water than our normal clay soils and produce healthier plants. Shelf life of plants treated with gypsum is extended by two or more weeks. Mushrooms grow better with gypsum as it encourages the growth of the aerobic bacteria they need.  Peanuts need the gypsum to receive enough of the calcium to develop normal kernels.  In industry it is also used in as a flux in the smelting of nickel ores, joint compound, PVC Pipe, and the manufacture of asbestos packing gaskets.

In a great many foods, gypsum is added as filler. All in all, the average human will eat about 28 pounds of gypsum in his or her lifetime as food additives.  Ice cream, spaghetti, vitamins and other pills all contain small amounts of gypsum filler.  It is also used as a coagulant in tofu and soybean curd.  You will also find it in baking powder, yeast foods, bread conditioners, canned vegetables, artificially sweetened jellies and preserves, and enriched flour to make breads and cereals. It is used as a filtration aid in sugar processing. You may use it as part of your nightly routine as it is in your toothpaste.  And of special note… Beer Making….(ahh my favorite!)  It is used in beer making to enhance fermentation and clarity as well as soften water. 

However, most of the use of gypsum is used in the form of Calcined Gypsum.  Wallboard (Sheet-rock) is made from calcined gypsum.  Due to its fire-resistant nature, it is a widely used building material. The US is the worlds leading consumer of wallboard at over 30 billion square feet per year.  Several industrial plants in Oklahoma only job is to make wallboard for this construction industry.

But for most of us, calcined gypsum most known use would be Plaster of Paris.  In the casting of metals, molds may be formed to make china dishes, dental equipment, silver implements, and metal parts of machinery.  Other uses of Plaster are medical casts, stage and movie sets, theme parks decors, sculptures, dentist molds, and craft items. Hey kiddies!  You use gypsum too as an additive to crayons.  Medical uses are as a Tablet Binder, Calcium Supplementation, Sustained Release Excipients, and Time Released Matrix for Surgical Applications (medicines are inside small gyp pellets which dissolve very slowly and then release the medicine sometimes days after the surgery). Anhydrite Gypsum is used as a filling and packing material in the coal mining industry and is used to fill cavities in mine roofs and spaces above road arches.

Bad Gyp

Bad effects of gypsum are rather limited.  One knows from caving that a bit too much of cave water full of dissolved gyp is the best (and fastest) laxative in the world!  And that caving though cave water with dissolved gyp will dry your hands out in a hurry!  Or having a 20-ton bolder of gyp land on you will can really ruin your cave day. First aid one can worry about while caving would be if in the eyes, wash thoroughly.  If on the skin, wash with soap and fresh water (not dissolved gyp cave water! <grin!>).  If having problems breathing because of dust, move to fresh air.  There is no personal protection or sanitation procedures to be followed by the CDC when working with gyp other than breathing dust particles.  But other than caving, how is gyp bad?

Breathing in of the dust seems to be the main health factor.  Breaking down wallboards and the process of making wallboard (or crushed gypsum products) is the only way one can in a long term exposure be affected by Gypsum dust. Gypsum dust is an irritant and can mess with the membranes of the respiratory tract and eyes.  Prolonged breathing of the dust can result in Conjunctivitis, chronic Rhinitis, Laryngitis, Pharngitis, Impaired sense of smell and taste, bleeding from the nose, and reactions to the tracheal and bronchial membranes.


Whereas use of gyp on farmlands leads to more air spaces in the soil and thus holds on to water retention, too much actually makes the soil too porous and the soil dries out faster than normal.

And really stretching it for this gypsum article is that Stachybotrys chartarum (which is a greenish-black mold) grows on the paper of wallboard and is the number one hazardous mold in the indoors.

Other Gyp Stuff

There are three states that have a city called Gypsum:  Colorado, Kansas, and Ohio.  Gypsum can be bought on if you’re into pretty rocks.

Oklahoma has nine of the top hundred of the World Longest Gypsum Caves: *2


Russia (actually Ukraine) has the top six longest gypsum caves.

So now you Oklahoma cavers, next time you’re in the western part of the state bellying though a mud crawl, stop for a second and say howdy to this wonderful Oklahoma resource!  After all… you are visiting its home!

References (as of January 2008)


Page Updated : March 6, 2008