Hi, In repairing the turquoise sculpture it seems to me that you have
two possible approaches. One you might call the restoration approach,
the other, simply a repair.
If the piece is valuable and significant (which is a judgment call,
perhaps to be made by an expert), it would probably call for a
restoration, that is, a repair that is reversible, that can be undone
later, and moreover be undone as far as possible without leaving any
visible traces on the piece. With turquoise, I’m not sure how I would
go about achieving this, since the stone is usually quite permeable,
and any ahesive, particularly a low-viscosity, “watery” one would be
likely to be absorbed into it, with two effects: it would leave a
line of discoloration along the fractures, and two, would be
virtually impossible to remove later.
On the other hand virtuallly ALL turquoise today is impregnated in
some way (with a plastic resin, sometimes even just with wax) to
enhance the color and make it less permeable. The hot needle test may
be helpful here - put a hot needle against an inconspicuous part of
the sculpture and see if it sends up a little tuft of smoke that
smells like burning plastic or wax. If it is already impregnated, as
it is likely to be, diffusion of an adhesive should be both less
pronounced (since the pores will already be sealed with the
impregnating substance) and less of a restoration issue.
If it is to be simply a repair, where you’re going for maximum
strength and permanence, without concern for the restoration issues,
I’d use a strong, slow-curing, two-part epoxy such as Araldite mixed
into a paste with turquoise dust (grind some matching turquoise to
fine dust in a mortar). This should yield a joint which in the worst
case is reasonably inconspicuous and if you’re lucky, is nearly
Any excess adhesive after curing can be sanded away with
progressively finer silicon carbide paper glued to a popsicle stick
or similar. Finish with say 1,200 or 1,500 grit and then polish.
A final caveat is that if the turquoise is paraffin impregnated this
could impede the expoxy bond.
Hope that helps…