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Oiling Tourmaline


#1

Does anyone know how to oil tourmaline? I have some rough
pieces suitable for wire-wrapping but they aren’t very shiny. I
bought a nice piece last year that the dealer said had been
treated with mineral oil. Has anyone had any experience oiling
tourmaline? I don’t know if I should just soak it in mineral
oil, heat it & soak it, or just rub it on? Thanks.

Carol W.


#2

hi carol i think you would do a lot better getting a small
vibratory polisher to tumble polish your tourmaline than oiling
it, any detergent will remove the oils from the surface and you
will be back to your dull surface. gesswein and rio grande both
have nice machines at a resonable price ask for
their 800 numbers and get yourself a catalog


#3

Bill Ehney Carol W. have been custom cutting gemstones for
quite some years now, and this is the first I have heard of
"oiling" Tourmaline.

I suppose if the stone had bad fractures, you could force oil
into them somehow, but can’t believe it would stay. Opticon
might work, but surely not mineral oil.

If the stone simply doesn’t shine, it probably is not well
polished. stones with many fractures are difficult to polish,
simply because there is not a smooth surface to polish.

You might want to go back and have a conversation with your
dealer

bill


#4
 Does anyone know how to oil tourmaline?  I have some rough
pieces suitable for wire-wrapping but they aren't very shiny. 

G’day Carol; I don’t think you should oil the tourmaline rough.
That process is simply to fill and disguise any flaws, not to
’make it look shiny.’ You see, the shine from oiling is so
transient that when worn for a few days it will soon become dull
once more. To say nothing of traces of oil on the wearer’s
clothing. Tourmaline will take a brilliant see-your-face-in-it
polish when subjected to the usual grinding, sanding through
several grades of wet-and-dry papers, then polishing with tin
oxide on a leather buff, by diamond polishing material, etc. It
could be varnished but that too will look awful inside a month
or so.

My suggestion for what it is worth would be to wrap it au
naturelle, or let a lapidary do his best with it. Or perhaps we
might persuade you to become a fledgling lapidary yourself?
Cheers anyway,

        /\
       / /
      / /      Johnb@ts.co.nz
     / /__|\
    (_______)  In sunny temperate Mapua NZ -

Autumn’s here and the fruit harvest is nearly done. Coolth in the air now.


#5

Carol, Putting oil on the surface of tourmaline might
temporarily give an oily luster, but it’s going to rub off.
Oiling would not really be a good substitute for external
polishing of the stone or removal of minerals.

If there are minerals on the surface of the tourmaline, then
Oxalic acid can be used to remove some of them. It may also be
used to remove material from growth tubes in tourmaline, and
sometimes to bleach those materials in the growth tubes to
improve chatoyancy in cat’s eye type tourmalines. Occasionally,
an epoxy sealer is then used to prevent dirt from getting into
the tubes. But the tubes have to be open to the exterior for the
sealer to work. Oiling is a relatively common treatment for
emeralds to fill air spaces in growth tubes, cavities or
fractures, where there are openings that reach the surface so
that the oil can reach the interior. The oil fills the air paces,
making the light move through the stone more evenly, and thereby
returning more light (and color) to the eye. It is a reversible
treatment and can be removed and redone by a professional every
few years as needed.

GIA’s Gem Reference Guide does not list oiling as an enhancement
to tourmaline.

HTH,
Carol

| Carol J. Bova @Carol_J_Bova |
| Faceted Emeralds, Tourmalines, Garnets & more! |
|Morro Redondo Cat’s Eye & Bicolor Tourmaline Rough|
| P.O.Box 5388 Glendale, CA 91221-5388 USA |
| http://www.bovagems.com/eclectic/ |
’’


#6

Hi Carol,

Sometimes rough stone dealers oil parcels of rough to aid in
examining the inside of the stones. The oil reduces the
dispersion caused by the rough, unpolished exterior. The reduced
dispersion makes it easier to examine the interior of the stone.

I’ve seen several types of rough treated this way, it’s quite
common.

Oiling tourmaline is not meant as a treatment to make it sell
easier. However, that’s not to say someone may not try it to pull
the wool over the unsuspecting/unknowledgable buyer.

Dave