Iridium is what

Iridium is what? This element may not be well understood by many people, and here is the introduction to it:

Iridium: atomic number 77, atomic weight 192.22, the element name comes from Latin, meaning "rainbow". In 1803, a British chemist tennant, French chemist's scottie dissolved in aqua regia coarse platinum, from the residue in the bottom of the vessel discovered two new elements in black powder - osmium and iridium. Iridium is one in 10 parts per million in the earth's crust, and is often scattered in various minerals in alluvial deposits and sediment deposits. There are two isotopes in nature: iridium 191 and iridium 193.

The artificial radioisotope 192Ir is obtained by neutron radiation from the stable element 191Ir.

The decay emits gamma rays, a half-life of 74.2 d, often used for industrial testing. (normally after ten half-life radioactive material, the radiation intensity is not enough to cause harm, industrial flaw detection using iridium source is a relatively safe choice.