From http://www.marlowcasinochips.com/links/davidspragg/borland/borlandhotstamp.htm

"Counterfeit chips are invariably found in mint condition. Where an existing chip was copied the chances are that it will show signs of wear from use in a casino. In some cases the color of the chip body is slightly different to the original chip that it matches (as the pictures provided are from different sources and cannot be guaranteed to represent 'true color' I have made no comparisons below). On many if not all of Borland's chips, the hot-stamping is in a slightly darker gold leaf (bronze?) than the original chips. The last thing to note is 'alignment'. Borland took great care in making sure the hot-stamping on the vast majority of his chips was correctly aligned ('medal alignment'). That is to say on the 'Nevada' mold chips, the word NEVADA appears directly at the top of the chip, and in the case of the 'DieCard' mold, the 2spot/5 spot dice appear at the top. This alignment occurs on both sides of the chip. Legitimate hot-stamps will not normally be so aligned (unless it happened by accident)."

So, the one on the left is real, the one on the right is a counterfeit.