Triplet structure

I have an opal triplet (6mm rd) that is a bit too high for the
setting I wish to use. What is the purpose of the bottom, black
layer? Can I remove a little by sanding to make it fit? How about
(gasp!) a bit of glue if the prongs are a mite short?

Thanks for suggestions,
Bob B

Bob

I have often sanded away part of the bottom of triplets to get
them to fit the setting with no problems. Just don’t take it all
away as it holds the sliver of opal in place. Harry

Bob,

The purpose of the black layer–usually onyx or similar–in a
triplet is two fold…it adds strength and stability to the thin
slab of opal, and it causes the opal to appear blue-black,
imitating a black opal. Stability is also added, to a bigger
extent, by the top layer, which is usually clear quartz.

Assuming that you actually have a triplet (three layers …onyx,
opal, quartz) instead of just a doublet (two layers …onyx,
opal), you could safely remove a little of the onyx, making sure to
leave enough to maintain the desirable blue-black color.

Glueing (sp?) is also a viable (and in my opinion preferable)
option. Five minute epoxy or other quick drying epoxy-type glue is
ok. Glueing leaves you with the problem of a high crown on the
opal, but assuming that you have a triplet, the crown of the gem is
actually quartz and so is sturdy and scratch- resistant.

Mike…Maryland…Eastern seaboard of US

 I have often sanded away part of the bottom of triplets to get
them to fit the setting with no problems. Just don't take it all
away as it holds the sliver of opal in place. Harry

Interesting . . . a “sliver of opal” and yet the cost of these are
quite high . . . are they more durable than regular opal???

Thanks for any info!

 Interesting . . . a "sliver of opal" and yet the cost of these
are quite high . . . are they more durable than regular opal??? 

there will probably be lots of replies to this, but . . .

Compared to “regular opal” (opal solids) doublets or triplets of
similar quality should be LOTS cheaper. They may be high relative
to comercial grade white opal, but that is because of the assembly
cost and because the sliver of opal is thin, but of a fairly good
grade. Remember that a triplet composed of a quartz cap, sliver of
opal and black jade or similar black background is an imitation
black opal and black opal prices for anything with any fire to
speak of are in the $100/ct and up range. Fine grade averaging
about $600/ct for blue greeen and $2000/ct for red-orange. And
that’s for 7 out of 10 grade. Top red-orange in 1 to 10 ct size is
up to $12,500/ct. I would expect the triplets you are talking
about are $10 - 20/ct. Price list I have gives $48 tops for an
extra fine (10 out of 10) 8x10 triplet.

And, yes, they are more durable because the fragile opal layer is
about totally protected, the quartz cap is harder than the opal,
and the black jade is tougher than the opal. Much better than a
solid opal for an everyday wear ring. Can be very pretty, too.
Might fool some, but NOT in the same class with good black solids.
Don’t wear it unless you can afford to loose it, tho. Cracked opal
is virtually valueless — would have to recut to a smaller,
uncracked stone.

HTH,
Roy (Jess)

 Interesting . . . a "sliver of opal" and yet the cost of these
are  quite high . . . are they more durable than regular opal???

Decent opal of any kind is very expensive. Triplets and doublets
utilize high-quality opal that occurs in structural forms that
cannot be used to cut “naturals” or “solids” (too thin, “wavy”
patterns, etc.) Logically it would seem that using less opal would
result in greatly lowered costs to the end user, and it does -
when you’re comparing apples to apples. Triplets are made to
duplicate the appearance of black opals by gluing a thin layer of
opal to a black backing material. A “sandwich” is then made by
placing a protective layer of glass (now common) or clear quartz
on top, which adds durability. But when you compare a triplet
with a black opal “natural” of similar size and visual pizazz the
price difference is simply awesome! Solid black opal prices in 5
digits PER CARAT are commonplace while most triplets sell for a
few dollars each.

If anyone thinks triplets are overpriced they should try making
one. Apart from the cost of the necessary (expensive!) equipment,
the labor involved is many times that of cutting solids, and the
materials are expensive, too. While assembled opals are designed
to resemble the appearance of black opals, they can also become
desirable rarities on their own. Unusually large and fine
triplets, especially some from the Spencer, Idaho opal mines, are
named and command very high prices. (Triplets from this location
can also exhibit unique and very valuable natural opal cat’s-eyes
and 3-legged stars; I own a couple of each). So while the general
run of triplets should be considered essentially as “costume
jewelry,” there are major exceptions to this rule. And fine
doublets with thick opal layers sell for many hundreds of dollars.

It should also be mentioned that triplets and doublets are made to
preserve rare and beautiful opal, not with any intent to defraud
buyers. But there are always those who will misrepresent them,
either through ignorance or greed, and there is an unfortunate
public misconception that anyone who sells assembled opals is
trying to perpetrate a fraud. Not true. Doublets and triplets
should always be sold “by the piece,” not “by the carat” because
so much of their weight consists of materials other than opal. If
they are properly priced and explained to the buying public, they
offer jewelers excellent lower-end price-points for customers who
love opals but can’t afford $100 a carat and up - way up!

Rick Martin