1. Gypsum USGS Eurico Zimbres FGEL/UERJ GNU Attrib-NoCom: cobalt123 USGS Attrib-NoCom-NoDerivs: skylarprimm

2. Gypsum precipitates (white) at a fumarole on the island of Vulcano in Italy. © Jürg Alean / Stromboli online Attrib-NoCom-NoDerivs: SamuraiCatJB Gypsum is one of the salts left when saline water evaporates from a lake or sea. Gypsum in caves can form needle-like crystals that radiate from clusters on the cave floor. Wind Cave/NPS Attrib-NoCom-NoDerivs: SamuraiCatJB

3. The mountains around White Sands National Monument contain gypsum-rich limestone, which you can see as the light-colored rock in the mountains. NPS/ White Sands National Monument Over a long period of time this has formed piles of gypsum sand, or dunes, in what we now call White Sands National Monument. Rain dissolves the gypsum in the mountains, and the water carries it into the closed basin lake below. As the lake evaporates, gypsum crystals form and then get blown about and crushed by the wind. Attrib-NoCom: The Horror Attrib-NoCom-NoDerivs: SamuraiCatJB

4. Stele of Ushumgal, Early Dynastic I; 2900–2600 B.C.; Mesopotamia, Umma (modern Jokha) (?); Purchase, Funds from various donors, 1958 (58.29); www.metmuseum.org Alabaster (pure gypsum) is easy to carve. Head of a man, 3rd–4th century; Southwestern Arabia; Alabaster (gypsum); H. 9 7/16 in. (24 cm); Purchase, Mr. and Mrs. Nathaniel Spear Jr. Gift, 1982 (1982.317.1); www.metmuseum.org

5. Many cultures carve alabaster. Ministry of Culture and Sports of Guatemala public domain Attrib-NoCom-NoDerivs: mike nl public domain Attrib-NoCom-NoDerivs: Jehsuk

6. Gypsum is extremely useful in construction. Ground gypsum and vermiculite (mica) are pressed into inch-think sheets of wallboard, also known as sheetrock or drywall. USGS Attrib-NoCom-NoDerivs: Stef Noble public domain Attrib-NoCom-ShareAlike: Vincent Ma

7. Attrib-NoCom-NoDerivs: mr.enigma Attrib-NoCom-NoDerivs: Gary and Kristie Attrib-NoCom: lucylouwho Both wallboard and joint compound are made of gypsum. USGS

8. Attrib-NoCom-ShareAlike: pwilnyc Attrib-NoCom: Quasimondo GNU Plaster, made of gypsum, is a sculpting and a molding material. CVC / Architect of the Capitol Attrib-NoCom-NoDerivs: Haylstorm's Head

9. Plaster casts of gypsum are often made of teeth before dental work is done. Copper dental mold (right) and plaster cast (left). public domain Alcatraz Island/USPS/DoI Attrib-NoCom-ShareAlike: little_hedgehog

10. Plaster casts are made from Plaster of Paris (gypsum that has been heated). Attrib-NoCom-NoDerivs: kden604 Attrib-NoCom: Harry Richards Attrib-ShareAlike: schwa23

11. Gypsum can be used as a conditioner to improve soil: this farmer uses processed sheetrock scraps from building construction. Oakridge National Laboratory OSHA TI/DoL Attrib: leighblackall Gypsum is added to concrete as an admixture before it is poured. Attrib: tuppus Attrib-NoCom: arimoore

12. Attrib-NoCom-NoDerivs: telsky GNU public domain Gypsum is a filler in paper, chalk, paint, and toothpaste. Attrib-NoCom: Leo Reynolds Attrib-NoCom-NoDerivs: R80o Attrib-NoCom-NoDerivs: Ryan Ozawa Attrib-NoDerivs: Matt McGee

13. Gypsum USGS Eurico Zimbres FGEL/UERJ GNU Attrib-NoCom: cobalt123 USGS Attrib-NoCom-NoDerivs: skylarprimm

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