Crookesite Crookesite Crookesite is a selenide mineral composed of copper and selenium with variable thallium and silver. Its chemical formula is reported either as Cu(Tl,Ag)Se or (Cu,Tl,Ag)Se. It is formed by precipitation from hydrothermal fluids, and contains by mass: 16.3% Tl, 47.3% Cu, 2.9% Ag, and 33.6% Se. Crookesite is an opaque, bluish grey to pink toned brown metallic mineral crystallizing in the tetragonal system. It has a Mohs hardness of 2.5 to 3 and a specific gravity of 6.9. It was discovered in 1866 in Skrikerum, Sweden and named for Sir William Crookes (1832–1919), the discoverer of the element thallium.
CU Scarborough CU Scarborough CU Scarborough is a Higher Education institute owned and governed by Coventry University. CU Scarborough launched in 2015 and currently operates in the North East coastal town, Scarborough. The first cohort of students studied classes in Scarborough Spa, before moving into a £14 million purpose-built campus in Scarborough. Student-oriented facilities include the following: CU Scarborough is part of the Scarborough £50 million education and sport campus, with the neighboring Sports Village operated by Everyone Active, offering state-of-the-art facilities including an Olympic Legacy swimming pool, a four-court sports hall, a multi-activity room, 60-station fitness suite and a community football