Rich won a chip recently on ebay as part of a Borland Commemorative 'lot'. It looked like The scarce Mint $1 black. However, something didnt look right and he started to clean it. It started to turn blue (look at right hand side of top right pic). The corresponding edge which you cant see went right back to the blue of the original color (see genuine chip below it). He sent the chip to me (Thank you Rich!). I could see immediately that it seemed to have been painted with a grey/black 'powder'.
I then noted that the inlay on the reverse had started to peel. Im not sure if that was as a result of Rich's vigorous cleaning as it looked like an attempt had been made to re-stick it. However, when I looked further I realised that the recess for the inlay had not been routered out and I was in fact looking at a blank chip that someone had faked the color on before sticking on inlays that had presumably come from a genuine $1 blue.
Without a genuine black for comparison it would not have been possible to know it was fake from the ebay scan, but when you see them all side by side you can.
For clarification, the fake chip (front and back) is shown on top, with the genuine black and blue below.