The U.S. Department of Agriculture (USDA) regulates whether cuts of beef can be labeled as lean or extra lean based on their fat and cholesterol content. Lean cuts of beef The USDA defines a lean cut of beef as a 3.5-ounce serving (about 100 grams) that contains less than:
â¢ High-Calcium Limestone: â¢ Magnesian Limestone: Lastly, some dolomites contain an excess of magnesium (Mg) and are called magnesian dolomite or high-magnesium dolomite. The excess magnesium is probably in the form of magnesium carbonate minerals, of which magnesite (MgCO3) is a possible candidate. It is used as a soil conditioner to neutralize acidity and to add calcium and magnesium nutrients. 2  Quicklime is calcium oxide (formula CaO) that is produced by calcining (burning) high-calcium limestone in a lime kiln to drive out the carbon in the form of carbon dioxide gas (formula CO2).
Jupiterimages/Photos.com/Getty Images. Limestone is a sedimentary rock composed of a mineral called calcite, which has the chemical formula CaCO3. Together with the dolomites, a related class of sedimentary rocks, limestone makes up some 10 to 15 percent of all sedimentary rock on our planet.he first element found in limestone is calcium; the symbol for calcium is Ca. Calcium has atomic number 20, meaning it has 20 protons in its nucleus.