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Gypsum: The Evaporite Mineral

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What is Gypsum

Gypsum is a soft sulfate mineral, composed of calcium sulfate dihydrate. Gypsum is an evaporite mineral most commonly found in layered sedimentary deposits in association with halite, anhydrite, sulfur, calcite, and dolomite. Gypsum (CaSO4 2H2O) is very similar to Anhydrite (CaSO4). The chemical difference is that gypsum contains two waters and anhydrite is without water. Gypsum is the most common sulfate mineral. A massive fine-grained white or lightly tinted variety of gypsum, called alabaster, has been used for sculpture by many cultures including Ancient EgyptMesopotamiaAncient Rome, the Byzantine Empire, and the Nottingham alabasters of Medieval England.

Gypsum Production and Resources Worldwide

The total global production of gypsum from mines in 2020 amounted to an estimated 150 million metric tonnes. This quantity is a notable decrease from the 2016 production volume of 261 million metric tonnes. As the world’s largest producer of gypsum, the U.S. also has the world’s largest reserves of gypsum. In 2020, U.S. gypsum reserves totaled some 700 million metric tonnes.

In 2020, the world’s largest producer of gypsum from mines was the United States, with a production volume amounting to 22 million metric tonnes. The next-largest global gypsum producer is a tie between Iran and China, both producing 16 million metric tonnes that year, with Turkey and Thailand following in top 5 world producers.

(Sources: US National Mining Association, US Geological Survey, Statista GmbH, Eurogypsum aisbl, Wikipedia).

Gypsum's Main Uses and Applications

  • Architectural uses (wall board, plaster of Paris)

  • Absorbents (ground control, drainage)

  • Floor Screen (Gypsum Cement)

  • Decorative (Decorative stone, plaster castings)

Gypsum main uses include: manufacture of wallboard/ drywall, cement, plaster of Paris, soil conditioning, a hardening retarder in Portland cement. Gypsum is also used in fertilizer, as well as blackboard and sidewalk chalk, among other products. 


Varieties of gypsum known as "satin spar" and "alabaster" are used for a variety of ornamental purposes; however, their low hardness limits their durability.

Gypsum can be milled mixed with water and then resume its original rock-like state. This means it can be shaped and hardened. Gypsum also has a “closed recycling loop”, meaning it can be endlessly recycled while maintaining a high quality.

Gypsum in Canada

Approximately 75% of Canadian production comes from Nova Scotia; Ontario, Manitoba and BC also produce gypsum. Wallboard manufacturers are located in these provinces as well as in Québec, Newfoundland, New Brunswick and Alberta. Crude gypsum is a low-cost, high-bulk mineral commodity. 

The present structure of the gypsum industry in Canada is expected to remain about the same, although future availability of synthetic gypsum resulting from more strenuous environmental controls will substitute for natural gypsum in some regions. The recycling of scrap and waste gypsum from construction sites and wallboard manufacturing lines will continue to become more important in both Canada and the US.

(Source: The Canadian Encyclopedia).

EDM and Gypsum in Nova Scotia, Canada

Gypsum mining was one of Nova Scotia′s most consistent industries for more than 100 years. The province produced approximately 80 per cent of the total Canadian gypsum production, and six per cent of world gypsum production. Nova Scotia is known for the quality and size of its gypsum deposits, as well as access to economical ocean cargo transport. Many of the gypsum mines in Nova Scotia have either shut down or been placed on care and maintenance indefinitely.

(Source: Nova Scotia Department of Lands and Forestry)

Nova Scotia is home to the world′s largest open pit gypsum mine at East Milford.

The Scotia Mine is located 10 kilometres away from National Gypsum's Canadian subsidiary - National Gypsum (Canada) Ltd. - which operates the largest open-pit gypsum mine in the world in the town of East Milford, Nova Scotia. The Milford-area mine has produced more than 134Mt of gypsum since it opened in 1954.


National Gypsum Company is a private company, incorporated as New NGC, Inc. in 1993 and headquartered in Charlotte, North Carolina, that produces drywall gypsum boards in the US. It has 17 gypsum board plants in the US and presents itself as a fully integrated building products manufacturer. It is one of the six producers which hold approximately 81% of the worldwide wallboard market (Georgia Pacific, Knauf, Continental Building Products (which was acquired by Saint-Gobain in 2020, National Gypsum, Saint-Gobain, and Yoshino Gypsum Co., Ltd.)

Other Atlantic Canada based gypsum mines:

  • Little Narrows, Nova Scotia - owned by CGC (idle at the moment)

  • Cape Breton, Nova Scotia gypsum mine - owned by Georgia Pacific (idle at the moment)

  • Melford and Sugar Camp, Inverness County, Nova Scotia - owned by Georgia Pacific (idle), and

  • Flat Bay, Newfoundland - owned by Red Moon Resources.

Milford - National Gypsum vs. Scotia Min

Gypsum Throughout History

Gypsum is a mineral that has been used as plaster for construction and decoration for thousands of years. Gypsum has been found in:

  • Floor screed in building remains in Israel, 7000 BC.

  • An underground fresco in the Neolithic city settlement of Çatalhöyük, Anatolia (now modern Turkey), around 6000 BC.

  • Mortar in the Cheops Pyramid, Egypt, 3000 BC.

  • Decorations and illuminated manuscripts throughout the Middle Ages and the Renaissance.

  • On the ceiling of the Sistine Chapel, in Rome. Michelangelo painted his masterpiece on gypsum plaster, 1508-1512

In 1888, the American Augustine Sackett invented a machine for producing plasterboard - also known as gypsum board, wallboard, and drywall - from layers of paper and gypsum. The first plasterboard plant was built in the USA in 1901.

In 1908, plasterboard manufacturing was improved by the American Stephen Kelly. He patented a gypsum core with a layer of paper on each side.  Modern plasterboard was born.

In Europe, the first modern gypsum plasterboard plant was built in the UK in Liverpool in 1917 and the second in London in 1926. In continental Europe, Latvia had the first factory, in Riga in 1938.

(Source: Eurogypsum aisbl)

Did You Know?

  • Gypsum is non-combustible and contains crystal water. These superior qualities are used in building elements that prevent a fire from spreading for up to 4 hours.

  • Gypsum provides sound insulation. Gypsum acoustic boards, used as part of insulation materials, provide a sound barrier between rooms and spaces.

  • Gypsum has a low thermal conductivity. When used with insulation materials for walls and linings, it can trap heat in rooms and buildings.

  • Gypsum can improve the impact resistance of areas that need strong walls, such as schools, public buildings and hospital corridors.

  • Gypsum is easy to install and to disassemble. At the end of use it can be completely recycled into new gypsum products.

          (Source: Eurogypsum aisbl)

Gypsum Industry News:

Global Gypsum: Your Online Portal for All Things Gypsum Related

Gypsum Association: Promoting the Growth of the Gypsum Industry in the USA and Canada

Canadian Gypsum News

Global Gypsum Magazine: July 2021

GP: How We Make Gypsum? 

Sources: The Canadian Encyclopedia, Eurogypsum aisbl, Georgia Pacific, Pro Global Media Ltd. - Global Gypsum, Nova Scotia Department of Lands and Forestry, Statista GmbH, US National Mining Association, US Geological Survey, Wikipedia

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