Meionite {Ca4Al6Si6O24CO3}:  Fl. magenta SW
Calcite {CaCO3}:  Fl. red-orange SW

The Noble Pit at Sterling Hill has outcrops of calc-silicate rock containing meionite (one of the scapolite minerals).  This often fluoresces a very subdued magenta-red in short-wave ultraviolet.  It is beautiful once your eyes have adjusted to the darkness of the room.

The non-fluorescent mineral in the specimen above is a clinopyroxene such as augite or diopside.

It's tough to get larger specimens from the outcrop, since the rock is so hard to break.  Calc-silicate rock is tough.  A 20-lb sledge seems so big and burly until you try using it on an outcrop of the stuff.  Then you might as well be using a 2-ounce tack hammer.

There are some loose pieces of meionite on the floor of the pit, however;  these have weathered to chalky white on the exterior.  Some of this still fluoresces fairly well.  When it's been outside too long, though, it develops a brown "rind".

Fluorescent meionite (with the possible exception of the Canadian variety known as "wernerite") does not display well next to willemite or scheelite;  I keep meionite and other dimly-fluorescing minerals down toward one end of my display shelves.  The best way to light this stuff is to have a D-68 or a Triplebright about 6 inches away from it.





Index of Photos

Main Page


Site contents copyright 2005, C. Thorsten


Back