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-SeeMe CU-SeeMe CU-SeeMe (also written as CUseeMe or CUSeeMe depending on the source) is an Internet videoconferencing client. CU-SeeMe can make point to point video calls without a server or make multi-point calls through server software first called a "reflector" and later called a "conference server" or Multipoint Control Unit (MCU). Later commercial versions of CU-SeeMe could also make point-to-point or multi-point calls to other vendor's standards-based H.323 endpoints and servers. CU-SeeMe was originally written by Tim Dorcey of the Information Technology department at Cornell University. It was first developed for the Macintosh in 1992 and later for the Windows platform