Guess the Cover of American Laboratory—October 2012

Correctly identify this month’s cover image and be entered to win a $10 Amazon gift card (one entry per person; you must be 18 years of age to be eligible. See contest rules at

This material, which is used in the fields of dentistry, medicine, and construction, has been in existence for centuries. The example shown here is from an 18th-century restored manor in New York. This image was captured using quantum dots excited by ultraviolet light. Can you guess what it is?

What do you think it is? Enter by leaving your answer in the comments section below. Stay tuned for the answer and for next month’s cover image!

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