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August 4, 2018, Calcium Carbonate

August 5, 2018
Greetings from the Bluff Park Back Porch, way up yonder on Shades Mountain (1,109′) in Alabama:
Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks as the minerals calcite and aragonite (most notably as limestone, which is a type of sedimentary rock build mainly of calcite) and is the main component of pearls and the shells of marine organisms, snails, and eggs. Calcium carbonate is the active ingredient in agricultural lime and is created when calcium ions in hard water react with carbonate ions to create limescale. It is medicinally used as a calcium supplement or as an antacid, but excessive consumption can be hazardous.


Calcium carbonate is widely used medicinally as an inexpensive dietary calcium supplement for gastric antacid[26] (e.g., Tums). It may be used as a phosphate binder for the treatment of hyperphosphatemia (primarily in patients with chronic renal failure). It is also used in the pharmaceutical industry as an inert filler for tablets and other pharmaceuticals.[27]
Calcium carbonate is used in the production of calcium oxide as well as toothpaste and has seen a resurgence as a food preservative and color retainer, when used in or with products such as organic apples.[28]


Calcium carbonate is added to many foods such as ready-to-eat breakfast cereals and cereal bars, milk alternatives such as soy or almond milk, and some baked goods. The Daily Value — developed by the U.S. Food and Drug Administration for labeling purposes — provides a set value for nutrients. The established DV for calcium is 1,000 milligrams, so a food with 25 percent of the DV for calcium would provide 250 milligrams per serving. A serving of Total Whole Grain cereal — manufactured by General Mills — provides 1,000 milligrams of calcium per serving. Kellogg’s Nutri-Grain cereal bars meet 20 percent of the Daily Value for calcium. Two Kellogg’s Eggo waffles contain 25 percent of the Daily Value. Silk brand’s soy and almond milks each contain 45 percent of the Daily Value for calcium or 450 milligrams in a 1-cup serving. Not all cereals, waffles and non-dairy beverages contain added calcium. Compare the Nutrition Facts labels to determine which brands meet your needs.
calcite. Icelandic Spar.
Calcite is the most stable polymorph of calcium carbonate. It is transparent to opaque. A transparent variety called Iceland spar (shown here) is used for optical purposes.
ArniEinOwn work

Calcite, Travertine.

Travertine calcium carbonate deposits from a hot spring
Conrad Dunkerson (CBDunkerson)Own work

Fossiliferous Limestone

Jim Stuby (talk)I (Jim Stuby (talk)) created this work entirely by myself. Transferred from en.wikipedia
Photograph (top) and etched section (bottom) of sample of fossiliferous limestone from the Ordovician Kope Formation near Cincinnatti, Ohio, showing brachiopods and other fossils. Collected 1998.

Calcite Crystal.  “Do you really want me to grind it up for my cereal?”

No automatic alt text available.
Sarbaiskoe Deposit, Kostanay Province, Kazakhstan
This specimen is considered to be one of the best calcites to have come out of Kazakhstan. Perched on a matrix of limestone is a large crystal of calcite in a beautiful golden-yellow color that is absolutely striking. The faces have a lightly frosted appearance giving the crystal a very soft and delicate translucency. Between the rich color and sculptural form, this specimen has great aesthetics and a lot of character.
Dimensions: H: 14 cm W: 7.5 cm D: 10 cm Wt: 640 g

Tums,  Calcium Carbonate.

Image result for Tums

Note:  Sylacauga Marble is a leading source of food grade calcium carbonate additives.

Sylacauga Marble, Calcium Carbonate.

Inline image

Deepest Limestone Cave in the World.  I bet that would have made a lot of Tums?.

Image may contain: outdoor
Q: How deep is Veryovkina Cave, the deepest cave in the world?
A: 2,212 meters
Veryovkina Cave, the world’s deepest known cave, is 2,212 meters deep. It is located in the Gagra district of Georgia’s Autonomous Republic of Abkhazia. Russian explorers discovered multiple rare species while doing excavations.
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