Sexually transmitted diseases (STDs) remain a major public health challenge in the U.S., especially among women, who. disproportionately bear the long-term consequences of STDs. For example, each year untreated STDs cause infertility in.
Chemically known as âcalcium sulfate dihydrate,â gypsum contains calcium, sulfur bound to oxygen, and water. Gypsum is an abundant mineral and takes forms including alabasterâa material used in decoration and construction as far back as ancient Egypt.hemically known as âcalcium sulfate dihydrate,â gypsum contains calcium, sulfur bound to oxygen, and water. Gypsum is an abundant mineral and takes forms including alabasterâa material used in decoration and construction as far back as ancient Egypt.
The four crystalline varieties of gypsum are sometimes grouped together and called selenite. Gypsum is a common, rock-forming mineral, with thick, extensive beds formed by the evaporation of extremely saline waters. It is often associated with other minerals, such as halite and sulfur. It is deposited from lakes, seawater, hot springs, volcanic vapors, and sulfate solutions in geological veins. Hydrothermal anhydrite in veins is commonly hydrated to gypsum by groundwater in near-surface areas.