FMF - Friends of Minerals Forum, discussion and message board

[Pete Richards]

Attached is a photo of dark brown wulfenite from the Globe Mine in Arizona. This is opaque and apparently the color is due to inclusions, perhaps of a manganese oxide. Some crystals have zones that are not totally opaque; here the color is grey to yellowish.

[Peter Megaw]

I have collected flats of stuff like this managnese-oxide included wulfenite at the Glove Mine and similar iron-oxide included wulfenite in the Defiance Mine. In both cases the pockets were zoned from almost unincluded clean crystals on the back of the pocket, and grading downward to the heavily included examples occuring on the floor and lower sides of the pocket. Some of the pieces occured in transition zones and along protrusions into the pocket where pieces showed a range of colors across 5-10 cm vertically.

John's comments about Chrome are well taken, there are a number of wulfenite occurrences here in central Arizona that are near ultramafic diabase dikes...these have high Cr and the wulfenites from these localities are typically a very strong red. Has anyone heard anything similar about the gorgeous red material from Iran?

Maybe we should change the name of this thread to Color in Wulfenite instead of colorless wulfenite.

[John S. White]

Through the wonders of the internet I have just heard back from Pierre Bariand and he wrote that the red color of the wulfenite from Iran is due to chomium. So, add another one to the chromium column. Thanks Pierre!