Characterization and identification of gems by the use of color filters has always been an appealing approach because of its affordable simplicity and the ease of examining multiple specimens.
For those who want the entire body of Dr. Hanneman's life work on Gem Filters - a tremendous value!
Ruby & Aqua Filter Set - Model 2001 - for Differentiating Red and Blue Stones, respectively
Synthetic Emerald Filter Set - Model 2002
Bead Buyer's & Parcel Picker's Filter Set - Model 2004
Auxiliary Filter Set - Model 2010 - Yellow Synthetic Sapphire Filter, Cape Line Color Filter for Spectroscopy, Red Filter for Crossed Filter Test, Chromium Fluorescence Filter, Standard Reference Color Filter, Describing Gemstone Color
Hodgkinson Method - Model 2004 - Gemstone Characterization w/o Instruments
Tanzanite Filter & Dichroscope - Model 1444 - with Pleochroism Table
Alexandrite & Color Shift Filter - Model 2003
PMCF Set - Model 2005 - Poor Man's Chelsea Filter
Jadeite Filter Set - Model 1450 - Stained Lilac and Stained Green Jadeite Filters
Using these filters is simple. Just place the stone on the included viewing surface, illuminate it with incandescent light, and hold the filter close to the eye. Observe the apparent color of the stone and match that up with the identifying chart that comes with the filter.
Please note: Actual set contains about 50 "luggage tag" cards.