By:  Hal Gelfius
ACGA Ethics & Authenticity Committee Chairman

Almost all cut glass lovers are aware that during the 1980s, a large amount of fake glass appeared on the market.  We do not have accurate information as to how much fake glass was produced, but we have been able to detect many pieces of fake glass because they would not fluoresce properly when put under a blacklight.

A good amount of 1980’s fake glass has been reappearing on the market — both knowingly and unknowingly — as many collectors are selling their collections or passing their collections to heirs who do not wish to keep it.  While collectors need to be more watchful, the black light test will still be an effective way to help determine the authenticity of these pieces.  The forgeries of the 80s will fluoresce pink; authentic pieces will fluoresce lime green.

More concerning in some ways is that lately we are seeing new fake pieces that will fluoresce green under a black light.   We don’t know much about the production of these fakes, but many knowledgeable people believe the blanks come from Eastern Europe and have been available in the market during the last 6-10 years.  The new fakes tend to fluoresce with a lighter green color — sometimes with a yellow tint — when compared to the fluorescence of early American Brilliant cut glass pieces.  Thus, the black light is not a valid test for these newer fakes.  It will be more time consuming but we have to dig further and look at other factors to determine authenticity of any suspected piece.

For collectors, the ACGA Ethics & Authenticity Committee recommends using the following criteria to verify authenticity.  First, use the black light to determine if the piece fluoresces correctly for the American Brilliant cut glass period.  Use a 15-watt, long-wave fluorescent bulb in a dark room.  Secondly, check to see if the piece is accurately cut to the pattern and that the cuts do not run past the point of intersection.  Many of these pieces have errors in the cutting.  Fakes will typically have diamond-wheel cutting which leaves small grooves in the glass.  Most of these pieces are acid polished which can be seen if carefully examined.   Thirdly, check the weight, thickness and wear marks on the piece.  Cut glass is heavy due to the high content of lead; a light piece calls for further examination.  Most glass has been used and shows wear marks and random scratches on the bottom and inside of the piece.  Many old pieces will have small nicks and abrasions.  If the piece is signed, it should be a sharp, distinct signature that is not smudgy-looking.  Finally, check the blank.  Is it a blank used in the Brilliant Period by that particular cutting house for the desired pattern?  A similar blank or one not used by a particular cutting house will indicate a potential fake piece of glass.  Take the piece to a window in daylight and look through uncut sections — the glass should be perfectly clear.  Blanks that are thicker or thinner than normal blanks or have a high spot in the middle are suspect.

I had heard about this fake (modern) glass that would black light green.  Recently, I had the opportunity to examine a piece firsthand.  The piece fluoresced with a very light green.  The cutting house that would have created the piece at the time it would have been made (1890s) would have created a piece that produced a dark lime green under a black light.  The cutting on the pattern was perfect as far as depth of cut but it was not cut exactly to the original pattern.  The cutting was so sharp that it hurt your hands to hold it and that is not normal.  The more intricate the cutting, the more it hurts to hold it.  There were no air bubbles or dirt specs in the blank and the blank was clear; there were no wear marks on the bottom.  The blank was a similar blank but not a blank this company used in this time frame.  The difference in the blank was not related to its diameter or height; where the sides of the bowl came in contact with the bottom, the radius was much larger than the radius in blanks from the early time period.  The piece was not signed, which was not unexpected.  The weight of the piece was perhaps a bit lighter than usual for that period but not enough to cause concern if that had been the only factor.  The thickness of the blank was appropriate and there was also no hump in the bottom.  Sadly, the other factors upon examination led me to believe the piece was not authentic American Brilliant Period cut glass.

All of the pieces I have had in my hands and examined have been cut with a diamond wheel.  Most of the pieces are acid polished and I think this was done to hide the diamond-wheel cutting marks.  I have found two pieces that I think have been acid polished and then wood polished — or polished in some other manner with something else — to cover the diamond-wheel marks.

In conclusion, fake pieces are appearing and becoming more and more difficult to detect.  Cut glass experts predict that, as we learn to detect problems in glass, forgers will be working to create new counterfeit glass.  For example, they are using wood polishing to remove diamond-wheel marks.  As in the past, rare patterns are the most susceptible to forgery as they typically generate the most dollars.  Every collector must be vigilant.  The Ethics & Authenticity Committee must be more vigilant.  Cut glass experts advise collectors to use caution when buying rare pieces without documented provenance.  They also advise that no single test should be used to determine authenticity.  As in all purchases, the rule is “buyer beware.”  All fakes I’ve found have been in the rare and expensive patterns by various cutting houses.  The more rare and expensive a piece or pattern, the more attention should be paid to its authenticity.  Determining authenticity will be more time consuming in the future.