The term "cremains" is a corruption of the term "cremated remains." It has fallen out of favor with most of the death-care profession as sounding too casual or disrespectful. See [[cremation]] in the ICCFA Wiki for more definition of cremated remains.
==Is it true that cremated remains can be turned into diamonds?==
Yes, there are companies that have developed a method combining intensely high heat and extreme pressure to turn the cremated remains - which essentially are carbon, of which naturally-occurring diamonds are made - into diamonds. They can do the same with a lock of hair.