This appears to be a new mold for the Reef $1 chip, with an error.

On the back of the chips, inside four of the diamonds, there are circular impressions (two of which I have circled on each chip).

On the new mold these impressions are much deeper.

On the new mold the tail (bottom left) of the $ is truncated/chopped off/missing. There is a single dot at the uppermost point of where the tail should end. Not only is ther no gold color here, there is also no impression for the tail of the $.

I could attribute the absence of gold color to a 'one of' glitch in color application. But the lack of a stamp or impression leads me to believe this is a sloppy mold, and probably the whole production run (or a large part of it) is like this.

If they use a serial production method (one mold stamping one chip at a time, single file) they would all be errors.

If they use a parallel production method (multiple molds, multiple rows of chips), or a batch process with x number of chips stamped out each cycle, then the number of error chips would be proportionately smaller.