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Repolishing Tanzanite?


#1

Hello all

I know nothing about stone polishing but…

A client brought in a Tanzanite that has the top facet edges worn
away but all other surface facets are in good form.

Is there any way that just the top can be polished without recutting
the entire top of the stone? …I don’t even know if this is the
right question…

A little kelp???

tkx
Simone


#2

Simone,

If you are saying that the table and the adjoining star facets are
the only ones abraded, then, yes, only those facets need to be
re-cut and re-polished.

But you’d better look closer, because if they are worn, the others
probably are as well.

Also, if you polish only the abraded facets, they will no longer
match the surface on the rest of the stone, in all likelihood.

Although hopes springs eternal, these jobs require a crown re-cut
most of the time.

I do 7-10 every week.

Wayne


#3
Is there any way that just the top can be polished without
recutting the entire top of the stone? 

Well, yes and no. Is it physically possible? Yes. Will it look good?
No.

Polishing just the table will in effect lower the table into the
crown. The crown facets will no longer point up they way they
should. The resultant facet pattern is likely to look cumbersome and
doctored with. Repolishing a crown is not usually costly (depending)
so there’s no compelling reason to do just the table.

Tanzanites will do that, abrade quickly. Prepare your client for
more wear on the stone in short order.


#4
Is there any way that just the top can be polished without
recutting the entire top of the stone? 

That’s an interesting question and I suppose it depends on the stone
under discussion, ie. how extensive the wear on the table edges -
and of course what shape it is. That’ll make a huge difference.

For a round brilliant, my assumption is that if you only recut the
table facet, the crown facets will no longer meet corner to corner
(table to kite - the kite’s top point will be cut off, star to star
will have a line separating them rather than point to point
meeting), and therefore you’d have to recut all the upper facets.
Even then it may be better to recut the whole stone. If it had a
thick girdle, then I’m guessing you could recut the upper facets
only, just leading to a reduction in height of the upper part of the
stone and therefore the overall height of the stone and the thickness
of the girdle would be reduced.

For a trillion, oval, pear, marquise, the same would apply I would
think.

For an octagon/emerald cut, then it is more likely that you could
get away with just recutting the table as the crown facets are
parallel to it so the facet to facet junctions are not as critical as
the other cuts.

Just my humble opinion based on observation of the different cuts
(I’m a wannabe faceter at heart) :wink:

Helen
UK
http://www.hillsgems.co.uk


#5

I repolish mounted and unmounted gemstone table all the time. For the
mounted stones I have a special fixture to be able to polish the
table. This works for stones whose prongs don’t extend up to the
table to interfere with the polishing.

Ed Katz, G.G.,
Jewels and Tools
(281) 568-5072


#6

Dear Mr Emery. is it true that diamond powder mixed with water
removes surface scratches from colored stones. i know that the
tazinite is VERY soft. could the fine diamond powder paste be applied
to paper and the table rubbed on it slowly? i do not concider myself
to be a stone guy but on occation I have marked a colored stone when
setting. My friend told me that the diamond powder is the fix. do you
agree? of course I am talking about a ring that is set and not ready
to be removed and recut.

thank you for sharing the

wayne werner “licking his VEGAS wounds”


#7

Hello all and thank you so much for sharing your knowledge.

I have shared all the info garnered here including that it is a very
soft stone and that it could happen again and that it could change
the look of the stone. The client has decided that she is willing to
try having just the crown repolished…by a power much greater than
I… and we’ll see how that goes…

I value this forum very much…
Simone