Monazite and Xenotime in European Rocks

Extract

As the phosphates of the cerium and yttrium groups, monazite aud xenotime, have proved to be quite widespread microscopic accessories in certain types of Brazilian granites and gneisses, "a batea test has recently been made on a number of hand specimens obtained from the mineral establishment of Dr. F. Krantz, of Bonn, for the purpose of determining if these interesting minerals were equally characteristic of the corresponding types of European rocks. About half of an ordinary museum specimen was crushed in a porcelain mortar to pass through a moderately fine sieve, concentrated in the batea and examined under the microscope after cleaning with the Thoulet or Klein solution, or both, and, when necessary, with the electro-magnet. The identifications of the minerals in the residues thus obtained, especially in cases of doubt, have been kindly revised by Dr. Eugen Hussak.