Per Teodor Cleve:
Per Teodor Cleve was a Swedish chemist and mineralogist.
Birth:
February 10, 1840 in Stockholm, Sweden
Death:
June 18, 1905 in Uppsala, Sweden
Claim to Fame:
Cleve was a Swedish chemist and mineralogist who discovered the elements holmium and thulium. He also discovered the element didymium was not an element at all, but two separate elements, neodymium and praseodymium.