1 The physical properties that identify this mineral for mineralogists and jewelers set this substance apart.

2 Mineralogist Jeffrey Post of the Smithsonian Institution in Washington, D. C. , agrees.

3 And so the mineralogist considers the relatively formless marble as a special formation of rock, differing from other equally special formations, such as sandstone or porphyry.

4 This jewel-like effect makes the giant crystals truly unique, according to John Rakovan, a mineralogist at Miami University in Ohio, who was not involved in the project.

5 The report included letters and attachments by other expedition members, including naturalist and mineralogist George Bird Grinnell.

6 "I am very excited about this paper, not only as a mineralogist but as a teacher and curator," says David Saja of the Cleveland Museum of Natural History in Ohio.