Selenite (mineral) was filled with mineral-rich water that drove the crystals' growth. The largest of those crystals weighs 55 tons, is long, and is over 500,000 years old. Gypsum occurs on every continent and is the most common of all the sulfate minerals. Gypsum is formed as an evaporative mineral, frequently found in alkaline lake muds, clay beds, evaporated seas, salt flats, salt springs, and caves. It is frequently found in conjunction with other minerals such as, copper ores, sulfur and sulfides, silver, iron ores, coal, calcite, dolomite, limestone, and opal. Gypsum has been dated to almost every geologic age since the
Mineral Products Association Centre was formed in 2003 and since 2009 has been part of the Mineral Products Association. The Concrete Centre promotes the use of concrete in construction through the provision of resources to enable designers to follow best practice for the design of concrete and masonry. The Concrete Centre publishes a journal, "Concrete Quarterly" which was first published by the Cement and Concrete Association in 1947. The journal showcases the use of concrete in construction projects in the United Kingdom and worldwide. The CQ archive is available online Mineral Products Association The Mineral Products Association (MPA) is the United Kingdom trade