Joined: Sun Jun 24, 2007 5:40 am Posts: 424 Location: Southern California
So, here I am, polishing the heck out of a slab of lapis lazuli with chrome oxide on leather, and what to my wondering eyes does appear? (Nope, not a fat guy with airborne livestock.) A rather nice shiny blue surface with green dots all over it! Not to mention the patina of green on the rough edges, which need to be rough lapis edges.
So the question: since running water and a toothbrush don't seem to get all the green off, does anyone have a trick for dissolving, floating, or otherwise removing chrome oxide from the cracks and crevices of a piece of lapis lazuli?
Joined: Wed Nov 15, 2006 9:44 pm Posts: 1079 Location: Washington State
Have you tried an ultrasonic cleaner? Works pretty well on mineral samples and old clocks. If you don't have one maybe your local jeweler does. There are a bunch of these on E-Bay in the $50 neighborhood and they are great for cleaning all kinds of stuff.
Joined: Fri Feb 24, 2006 1:20 am Posts: 2756 Location: Southern California, U.S.A.
An ultrasonic will work well but be sure to run it with water only or a totally non-acidic solution. Lapis is a rock and it's usually associated with calcite and other carbonates. Even very diluted acid will destroy the polish in an instant. I know because it happened to me when I used a commercial ultrasonic cleaning solution.
Joined: Sun Jun 24, 2007 5:40 am Posts: 424 Location: Southern California
Gearloose wrote:
Quote:
P.S. - Sue (my wife) wants to thank you, too. She loves the way her jewelry sparkles after a bath in the ultrasonic cleaner.
You know about Tanzanite, opal, and ultrasonic cleaners, right? Before something bad happens...
We know about opals, (we have only one) and included or filled stones (a nice pair of emeralds that came back from a jeweler looking shockingly dull comes to mind) but I didn't know about tanzanite. Have to file that away for when we get some. Thanks
Joined: Sat May 22, 2010 2:51 am Posts: 755 Location: South Africa
Gearloose wrote:
You know about Tanzanite, opal, and ultrasonic cleaners, right? Before something bad happens...
There's long list of gemstones that can suffer damage in ultrasonic cleaners, including such common ones as rutilated quartz and included sapphires (broken both myself). In fact, anything with inclusions is vulnerable. The more powerful the ultrasonic cleaner, the higher the risk.
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