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Repairing amber


#1

Well Orchidians, here I am again with a question about amber. A
customer has brought me an unusual piece containing a large fly. The
amber is clear and the fly is positioned nicely in the center of the
amber disc. The disc is about 30 mm in diameter and probably 15 mm
thick in the center. The disc has a convex (domed) surface and is
flat on the back. It’s from Chipas Mexico.

Anyway, the disc has cracked in two - right through the fly.  Does

anyone know if the disc could be glued securely. The crack would
still be visible, but the piece could be re-mounted and worn again.

This amber is brittle and won't take much stress.  Advice is

requested. TIA all you great people. Judy in Kansas

Judy M. Willingham, R.S. Biological and Agricultural Engineering 237
Seaton Hall Kansas State University Manhattan KS 66506 (785) 532-
2936


#2

Judy, ��� I have done some amber “repairs” in the past using Opticon
as the bonding material. It will cement the pieces together and it
will hide the crack in the amber itself (the fly will most likely
still show the damage). I use the clear version of Opticon rather
than the more readily available “amber” colored version. To do the
repair, spread a very thin coat on the two crack faces and align the
pieces back together slowly; starting at one edge and rolling them
into their final positions ( this reduces the likelihood of trapping
air bubbles in the seam); wipe off any excess that gets onto the
amber’s outside surfaces and allow the cement to harden to full cure
(depending on the room temperature, this should take about 24 hours).
Next, lightly sand off any cement that remains on the surfaces of the
amber (400 grit silicone carbide paper works great for this) and
finish by polishing with Zam polishing compound on a soft muslin buff
turning at a slow speed. ( I do this on the flexible shaft� to get
good control of the rate of rotation because too fast of a buff will
burn down into the amber’s suface).

Paul D. Reilly, (a first time responder after months as a lurker)
Wholsaler of repairs and custom work to the trade.


#3
        Anyway, the disc has cracked in two - right through the
fly.  Does anyone know if the disc could be glued securely.  The
crack would still be visible, but the piece could be re-mounted and
worn again. 

G’day Judy Willingham; my suggestion (for what it is worth) is that
amber is simply ancient lumps of resin from which all low temperature
volatiles have been driven over the centuries. If you have a piece
of scrap, you could dissolve a very small amount in real oil of
turpentine; not the stuff from the supermarket, but from artist’s
supply shops. Distinguishable by it’s pleasant ‘pine tree’ smell.
failing scrap, perhaps a little powdered ordinary resin would work
with the turpentine as a glue. You could treat it as lucite joins
are treated; paint the ‘pine glue’ over each of the exposed broken
faces, press together accurately, then with the piece resting on foil,
grease proof or other proofed paper on a small wood support, clamp it
gently, place it in your airing cupboard - well away from the hot
water cylinder, and leave it for a day or two. The join should be
barely visible. Perhaps it might be remounted in an electro formed
bezel? – Cheers now, John Burgess; @John_Burgess2 of Mapua Nelson
NZ


#4

I’m sorry that I don’t know how to repair cracked amber but wonder if
that is what you’re looking at. Natural amber with included insects
is most commonly irregular lumps or masses which contain multiple
insects and perhaps dust and plant material as well such that
polished specimens are more likely to be smaller and irregularly
shaped. The description of a clear, 30 mm disk with perfect placement
and crack raised my suspicion that the piece is a fake. Many fakes
have been made and the potential market has increased greatly since
Jurassic Park, etc.

Is the crack horizontal and in the same plane as the fly or vertical?
If horizontal, it would seem to futher support the possibility of
two layers of resin with a fly placed between pourings. Perhaps the
fly species would help the determination. I’m not an expert by any
means, but would not expect to see a “housefly” type in real amber,
though I have seen them in some fakes.

You can try the tip of a hot needle on an inconspicuous place (the
side or an edge of the piece) to check for the characteristic "piney"
smell of amber. If it is indeed authentic, I would suspect it is a
very valuable piece and perhaps another on this list could assist you
in its repair.

Good luck to you.


#5

Judy - the reason that the amber broke is two fold -

It wasn’t annealed, and second, the “amber” from Mexico isn’t really
amber, it is technically copal, or young amber. Gemmologically
speaking, amber is 40 million years old, anything else still has too
much volitile chemistry to be amber.

The most stress in a piece of amber is where inclusions are found, so
amber with insects is usually not annealed. Annealing is done at a
relatively low temperature, about 170 F, in oil. this results in the
characteristic discs, from spreading out the stress. If it is done
with buggy pieces, the discs would cover the bugs, thus removing the
interest and value.

Now to your question, yes you can glue the piece together, being as
the piece is from Mexico, you might try acetone to see if it softens
it. If so, it will make a nearly invisible bond. Acetone is often
used to “polish” copal grade material since it softens the surface.
In the event this doesn’t work, use nail glue - the stuff that comes
in a little tube for fake nails - it has a tiny applicator and
ususally works great. No I don’t do my nails - I work with this
jewelry stuff and haven’t had a manicure for years.

Good luck, I love amber, it’s color, weight, and warmth!

Judy - in steamy hot Denver, with a weeded garden and a sunburn.


#6

Judy, I’m not sure what “young amber” means, but…copal is the
product of the copal palm, which produces a thick resin which, as it
dries is (was) a common substitute for amber. But it is NOT amber.
The copal palm does not grow in Mexico, but Mexico is the source for
quite a bit of amber, actually.

Wayne Emery
Jewelry Design Studio
Author, “Jewelry Photofgraphy Made Easy”


#7

Attn. Pam-- Greetings; To test amber–Dissolve salt into hot water
until it stops dissolving, let cool…Amber will float, plastic will
sink… Enjoy— Dave.


#8

Attn. Judy-- Greetings; I suggest that you --with a diamond burr, grind
some amber dust,(scrap amber/like color), mix with 320 apoxy, and
fold pieces together. emery excess adhesive, and repolish whole
stone… Enjoy---- Dave.


#9

Re. Wayne Emery’s comments regarding copal coming from the copal palm,
that may be, but according to R. Websters fifth edition of “GEMS’,
copal is “a recent fossil resin” and is " the exudation from various
trees, and may come from various parts of the world, particularly from
the West Indian locust tree from South America”. The New Zealand
variety comes from the kauri pine and is called kauri gum. The best
copal is that which has been buried for a long time, but it is nowhere
near as old as true amber.

Jerry in Kodiak


#10

And much less destructive than hot needle! :slight_smile: Attn. Pam–
Greetings;
To test amber–Dissolve salt into hot water until it stops dissolving,
let cool…Amber will float, plastic will sink… Enjoy— Dave.


#11

Well all here is a little trade secret when I was at the Amber Company
we cut hundreds of kilos of Amber Baltic, Chiapan, Dominican, you name
it we were cutting it. the good chiapan Amber is much Like Dominican
Amber same basic age (slightly younger than Baltic if I remember
correctly Mexican/Dominican approx 30 million years old, Baltic 40 to
60 million years old). we used standard lapidary techniques to cut our
amber, and polished with cerium on wet leather (this only works on
natural amber, copal is to soft and usually just smears, heat treated
amber is recuttable but you may find the amber inside is a different
color usually much paler in color than the outside due to the heating
and treating of the amber, or the fact that most of the Baltic amber
used in the mass produced Russian and polish jewelry is reconstituted,
amber scrap that is melted back together). Any way to address your
problem we healed many pieces that exhibited cracks, or were broken
altogether, by heating very lightly( we used a dop pot) you don’t want
to melt it, or burn it, just drive out the moisture. Then use crazy
glue (cyanoacrylate) the very thin kind to fill the cracks it will
actually migrate into the piece, then spray with the accelerator to
make sure it hardens completely. you can then recut the piece. Amber is
basically a natural polymer(plastic) in mexico(chiapas) they hand sand
and polish with brasso metal polish and a hand rub, results are not
as satisfactory as true lapidary techniques but it works. crazy glue:
the brand I’ve always used is from Satellite city p.o.box 836 Simi
valley,CA 93062 805 522 0062 they have a nice variety of thicknesses
from thin to gap filling.

Alex