HOW TO SPOT RESTORATION ON MOST ARTIFACTS
If you want to locate restoration on an artifact, there's a couple tips to remember that will usually work without the aid of magnification, chemical treatments or specialized lighting. If you cannot find the restoration visually (which is my goal, by the way) I have two fool-proof tips for you. If you suspect there is a restored area, try this:
Stone is ALWAYS naturally colder than man-made materials. The difference in material temperature may be too subtle to feel with your hands but all is not lost.
Put the artifact to the edge of your lip, not in your mouth, just the skin under your lower lip near the edge. This area is best for determining minor temperature differences, and it is 100 times more sensitive than your fingers or cheek.
For example: If you slip the edge of an arrowhead across that skin, you will immediately and unquestionably feel the restoration because it will be drastically warmer. You will be able to feel it even if it's only 1/16 inch wide.
BANDING TEST - VISUAL
Banded slate is almost ALWAYS layered in straight flat layers of alternating colors stacked like the pages of a book. They are aligned on a single flat plane, and it is only the contours of the artifact that makes them look curved. If you were to look at the edge of the artifact you would be able to recognize that flat stack of layers and see the angle and how they align through the artifact. If you find the banding plane, it will look something like a bar-code with straight parallel lines. Teach yourself to see them on that plane and soon you will find that some restoration folks aren't aware of it. If you see banding that makes drastic angle changes away from the banding plane, then you have improper restoration. I use a laser mounted on my workspace to help me trace the banding plane around the contours of an artifact. Lining up the laser plane at the same angle as the banding plane allows me to trace the line accurately around any contour.