1) Mineral 
Thortveitite is a mineral consisting of scandium yttrium silicate (Sc,Y)2Si2O7. It is the primary source of scandium. Occurrence is in granitic pegmatites. It was named after Olaus Thortveit, Norwegian engineer. It is greyish-green, black or grey in color. A transparent gem quality example was found in 2004, and reported in `The Journal of Gemolo....
(from the article `rare-earth element`) ...is a by-product from uranium processing—the scandium, which may be present in amounts up to five parts per million, being recovered from the ...
[n] - a mineral consisting of scandium yttrium silicate
noun a mineral consisting of scandium yttrium silicate; a source of scandium