Hello Douglas and Sarah;
I haven’t actually worked any ammolite yet but I did pick up a few
pieces at our Provincial Rock Club Federation’s annual meeting back
in May. We also took a tour of the Korite Mine where ammolite is
dug out of the black shale near the St. Mary River in southern
Alberta.
The most common treatment is as you mention making a doublet if
there is suitable black shale on the back of your rough and bonding
a spinel or quartz cap on the front to protect the ammolite.
If there isn’t enough black shale on the back triplets are made by
bonding again a quartz or spinel cap on the front and then a black
material on the back. I have even heard of using black jade on the
back of the triplet and tempered glass on the front.
The most common bonding agents I have heard of is opticon and clear
epoxy.
As well some of the members in our local club have been coating the
pretty side of the ammolite with opticon/epoxy then after it cures
cutting the ammolite to the shape they want and then mounting.
I can’t say I’m a fan of this treatment; it just doesn’t strike me
as very durable nor does it give the magnification effect of a
convex cap
There are also a couple of sites on the internet with
instructions/details.
Hope this helps,
Mike O’Toole
in sunny and finally dry Calgary, Alberta