I am really puzzled. I have some sterling silver earrings which I
want to patina using liver of sulfur. They are set with lab created
corundum ruby, saphires, and alexandrites.
One of the articles in the April 2014 Lapidary journal states that
when using LOS one should finish the piece, but"do not set any
Stones should be set after patination."
However, I read somewhere else that soft stones, such as lapis,
turquoise opal etc. should not be submerged in LOS, but that it was
safe to use LOS on lab created gemstones which have been made from
corundum and are not porous.
Before I dunk the earrings in the LOS I thought I had better check
with the experts on Orchid who have come to my aid so many times.
Alma
Alma - the LOS won’t hurt your stones - but the bigger question is
what does the darkened area under the stones do to their color and
brightness.
Diamonds usually don’t matter, well cut ones reflect up. Other gems
not so much.
The softer stones usually aren’t affected by LOS - but might be if
you are using it hot. As a matter of practice, I use room temperature
LOS. It is slower, but lasts much longer. Depending on the design, I
sometimes paint it on the piece. Using it cold requires that the
metal be newly cleaned.
That doesn’t mean overnight, it means now. I use a 3M bristle disc
to clean off the metal, then apply LOS. It may take many coats of
LOS. Be patient.
I can’t see that there would be any damage to the stones from LOS.
If you are setting your stones in bezels the patina that will occur
inside the settings may not enhance the look of your stones. And once
the stones are set you will have to live with it.
Before I dunk the earrings in the LOS I thought I had better check
with the experts on Orchid who have come to my aid so many times.
Alma, LOS is not an especially reactive chemical or anything, beyond
it’s ability to form sulphides on silver or copper alloys. But it
does have that distinctive dark color, so it can stain things. Your
solid crystaline or glass materials will be fine, just as is the
metal which lets you rinse off the LOS. You might be better avoiding
dunking in stones that are porous and could absorb the LOS, staining
them. turquoise is a prime example, at least for the typical softer
unstabilized material. Good “persian” quality, relatively hard and
dense (for turquoise) probably wouldn’t be affected. Plain white
solid opal also is fine, but you’d want to avoid the sort of granular
materials that are sometimes “sugar/acid” treated, or some boulder
opals with porous rhyolite or limonite bases or inclusions. Similar
idea with Lapis. The sulphate in LOS might give it slight acidity
too. Not sure of that. But if so, pearls or acid sensative stones
like coral might also be better kept out. I don’t recall ever having
any trouble with malachite though, so that’s probably not an issue.
Your synthetics, or for that matter, natural stones like saphires,
tourmalines, topaz, etc, won’t be affected at all. Dunk away.
Thank you all for your helpful suggestions about dunking my earrings
with stones into the LOS. After reading Peter Rowes explanation of
what los is, and the fact that stones are impervious to
discoloration from it. I took adeep breath dunked a pair of the
earrings into the hot liquid, and to my delight, the silver turned a
lovely black and the stones came through as bright and clear as when
I first set them. They were tube set and I had left the backs open,
so there was no collection of LOS to deal with.