By John F. Berner/ EIC
Originally Published in the Central States Archaeological Journal, Vol.52, No.3, pg.126
May I treat this subject as a introductory matter? The reason is there have been some inaccuracies written about the use of these beneficial tools. Ultraviolet light, UV or “blacklight” as it is generally called is not new to the collector fraternity. However, it has more recently been introduced to artifact collectors. For more than 50 years, Museum curators, art dealers (especially those who specialize in fine art painting and ceramics) have used these tools extensively.
Basically, there are two types of UV lights; hard wired appliances which require an AC source of power, and more recently DC, battery operated. I have used both types extensively and find them to be convenient. The major difference is the size of the bulbs which are available up to 24″ in length with AC power cords which produce more light than typical DC battery types which are normally limited to 8 inch to 12 inch in length.
I have learned much from the treatise on black light and its application entitled “The black light book”, updated 4th edition by author Mark Chervenka. This book is a standard recognized by those who specialize in antique and similar collectibles. Mark is the editor of “Antique and Collectors Reproduction news”. In his book, he discusses the merits of long wave and short wave UV light. He is quick to state that using short wave light should be avoided because it will give false readings and dangerous.
Short wave is potentially dangerous as it can cause skin and eye problems from exposure. Persons who promote the use of both should be advised of such hazards. I assume this false information came from the application by professional gemologists who use both to determine the authenticity of precious stones such as emeralds and diamonds.
Long wave UV light can assist in determining a number of possible artifact problems that otherwise might be undetected by the human eye. First of all, it can be very effective in showing restoration which has become increasingly unnoticeable by today’s expert restorationists. Keep in mind that all UV examinations are best conducted in total or nearly total darkness because the illumination of the black light is minimal at best. And whenever possible, the subject of your examination should be displayed upon dark black cloth which has no reflective qualities.
The use of “black light” illumination is also very effective in revealing the differences between ancient surfaces, especially on flint and chert items where modern damage or rechipping might occur.
Depending upon the type of toolstone, the modern surfaces will either fluoresce as dark or light. And in some instances, the new or modern knapped areas may fluoresce different colors from patinated areas of thousands of years of chemical and physical changes. One toolstone in particular which gives instant readings is old and new Knife River flint, sometimes called “Coffee Agate” by Westerners. This highly attractive material is found in North Dakota and elsewhere and is highly translucent. Another easily discernable material is the popular Hornstones of the midwestern states. This material will show darkly where a fresh flake has been removed from the ancient surface. The white flint of Missouri and Illinois called Burlington chert shows a similar effect as new areas also show darker than the surrounding areas which have been anciently aged. This ancient age sometimes is removed by accidental damage, other times for the purpose of rebasing or repointing slightly damaged artifacts.
Please understand that no black light examination will reveal whether an artifact in question is ancient or reproduction!
Flint is determined by archaeologists as silica rock which is translucent, and chert is that silica material which is opaque. Most chert like materials including Jaspers will present an obvious difference between old areas and new areas. However the fine chalcedonies, agates and semi-precious gem materials will seldom give up the same type of answers regarding alterations with the use of Ultraviolet light sources.
Not trying to sing an old song but it is a good time to let our readers know that the use of the ” black light” has been a primary tool of many authenticators whose job is to advise collector owners whether not an artifact in question has been tampered with, restored, glued or obviously reworked by modern man. Restoration is usually not the major problem and in some instances may be overlooked or missed by the purveyor of the artifact.
I like to think of minor tampering as the originally harmless attempt of farmer finders to correct ancient or cultivation mistakes on artifacts. My mentor of artifacts in the 1940’s did not see any harm in correcting the non-symmetrical area of his finds. After all, he was a full blooded Cherokee and considered the changes his right!
Modern rechipping, resharpening or rebasing of ancient flints is something else! It is fraud and deception of the highest form. It is no different than the counterfeiting of money. Yet, there are those who condone the action of the deceitful.
One midwestern dealer had the audacity to brag that he has enjoyed more than a million dollars in profits from fraudulent work such as rechipped flint and ground stone reproductions. It is fact that several skilled flint chippers who can skillfully rework ancient points from base to tip and back were engaged. The new work is artificially aged and the item is ready for market!
This is where a “black light” can shine brightly as it may reveal this insidious attempt of work for all to see and you to know! Thank you for listening.
“Used by Permission of the Author”
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