Laboratory analysis of woodBy Mark Chervenka
In theory, one of the easiest ways to catch fakes, repairs and reproductions is to compare the material a suspect is made of to the material from a known original. But who of us can say if the wood in that mahogany table is Swietenia, central American mahogany as was used in early American furniture, or made of Shorea, Philippine mahogany and a present day reproduction?
The next time you are in doubt on the wood used in a piece, consider sending a sample to the Forest Products Laboratory operated by the United States Department of Agriculture (USDA). The public may send in up to five samples a year for free laboratory identification.
Samples should be a minimum of 1/8" thick and should be about 3/4 to 1" long. All samples should be cut with the grain. Samples must be split rather than shaved or gouged.
Each sample needs to be in a separate container (or envelope) and should include a written request for the analysis. Samples should obviously be taken from hidden areas. This might be under a seat, or the bottom edge of a table or inside a drawer. Remember that the sample needs to run with the grain and should be at least 1/8" thick..
If you are seriously interested in purchasing a piece but want a laboratory analysis, mention this to the owner and ask to take a small sample from a hidden area. You might want to show you're serious by saying that if the wood proves to be so-and-so, you'll take the piece. Most sellers won't mind the 2-3 weeks wait if you demonstrate you are seriously interested by this approach or similar offer. DO NOT take a sample without the seller's permission.
Contact the Laboratory for the latest requirements before sending any samples. You can reach the Laboratory at the following:
Center for Wood Anatomy Research
USDA Forest Service, Forest Products Laboratory
One Gifford Pinchot Dr.
Madison, WI 53726-2398
Phone and fax
Home page is: http://www.fpl.fs.fed.us/research/centers/woodanatomy/index.php (then click on Wood ID)