Greetings, I’ve been looking unsuccessfully for Jemeter Digital 90,
and found a device called the Jeweler’s Eye developed by Dr. William
Hanneman.
We travel through Asia, and to Tucson buying mostly inexpensive gems
for our jewelry line. We could use a quick and reliable way to
authenticate large quantities of gems.
The device looks OK, but I can’t find any references to it in
searches through Google or anywhere else.
Any feedback from experienced Gem folks would be appreciated.
Bram - You can contact Hanneman Gemological Instruments directly at
P.O. Box 942; Poulsbo, WA 98370. Phone: 360-598-4862. This info is
from the 2002 Lapidary Journal Buyers’ Guide.
Briefly, Dr. Hanneman introduced the Jeweler's Eye to the gem
community in the 1970s. It is his own creation, using a "new"
concept in optics, which he refers to (I’m remembering here)
“relative reflectivity”. There was a lot of brouhaha at the time,
and some unfortunate interactions by folks from places like GIA.
However, Hanneman’s concept, and the Jeweler’s Eye were vindicated,
and it seems a good instrument to have.
The Sarasota Instruments co. is defunct. The 2 types of Jemeter
they built occasionaly show up for sale. The digital version is
superior to the ‘analog meter’-type. recently some of both have been
sold on ebay. The price is outrageously high considering kassoy
sells a new reflectivity meter (instead of measuring critical angle
like a Pulfrich refractometer or Brewster’s Angle like the $1800
GAGTL meter)for $150. the Jemeter, hanneman’s meter and the Kassoy
(Presidium) unit measure luster or ‘relative reflectivity’ and,
while generally ‘good enough’ they have the drawback of being
affected by poor polish, and not being able to show birefringence.