| Ammolite 2: A Guide for Gemmologists, Jewelers and Lapidaries
By Donna Barnson
Published by Barnson, P.O. Box 179, Selkirk, Manitoba, Canada. 2001.
Softcover, color, 8” x 11”, 116 pages, $29.95.
Reviewed by June Culp Zeitner.
Few books have such beautiful color, but then few items in the gem kingdom
have such beautiful colors as ammolite, the fossil ammonite gem from Alberta,
Canada. This second volume of the history and use of ammolite gives much additional
information on how it is graded, cut, treated, and used. The vivid metamorphosed
shell was brought to the attention of lapidaries in the early 1970s, but its gemstone
possibilities were explored in 1969 by geologist Santo Carbone. The gem was first
marketed as Korite. Later, it was called calcentine, and then ammolite. Ammolite
is the name accepted by CIBJO — the International Confederation of Jewellers.
Although ammonites from some other areas have iridescent shells, only those
from near Lethbridge, Alberta, Canada have the necessary thickness, the well-preserved
aragonite, and the intense coloring and brecciated patterns suitable for lapidary
use. The genus for ammolite is Placenticeras. The iridescent ammonites are found
in the Pierre Shale and Bearpaw Shale formations.
The author gives the history of both ammonites and ammolite and then explains
the way the gem is used. It can be cut for several kinds of cabs, doublets, triplets,
or as solid pieces. About 90 percent of the gems are produced by Korite International,
a corporation founded by René Vandervelde.
Interesting chapters are the rules of collecting ammonites and how to restore
and prepare ammonites. Most of the mineral rights are already under the lease
in the known ammolite area of Alberta. The ammonites are found in concretions,
some as deep as 1000 feet below the surface. A backhoe is often used in the mines.
Good specimens and broken sections are transported to Calgary for cutting.
A well-illustrated chapter gives details on the cutting and polishing of ammolite.
There is also a per-carat listing of prices on natural, stabilized, and triplet
stones. A stabilized, 45- x 30-mm stone will cost about $462. The process of making
the popular gem triplets is described. Lampblack and epoxy are used for backings.
Assembled gemstones are cured in an oven. While the hardness of ammolite is only
4 on the Mohs scale, the quartz cap yields a hardness 7 gem. The best stones are
mounted in distinctive gold jewelry.
The vibrant color in this book is a real treat. (Ammolite is one of the fine
new gems of the 20th Century.) Gemologists and lapidaries — as well as owners
of ammolite jewelry — will certainly enjoy it.
June Culp Zeitner, who has been writing for the Lapidary Journal
since 1956 and joined the editorial staff in 1967, is the author of nine gem and
mineral books, and has helped to start the National Rockhound and Lapidary Hall
of Fame.
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