This variant have a more pronounced and detailed portrait of Dr.Jose Rizal.
OBVERSE: REVERSE:
As you can see this one has a more detailed portrait of Dr.Jose Rizal and a thinner rim. This passes the weight test and diameter test in case you're wondering if it's real. It does have the details of a Frosted coin.
Comparison between the Common Circulating 1 Piso 2013 Coin(L) VS. This "Variant"(R)
OBVERSE: REVERSE:
Hope y'all can see the difference, am editing this on mobile so it looks small for me, but as you can see the coin from the left has a not-so detailed portrait of Dr.Jose Rizal, thinner text and bigger rim which appears on every 2013 1 Piso coins in circulation while on the right side is the said unlisted variant, this one has a detailed portrait, bigger text on both sides and thinner rim.
Also, others have already found the said variant as there are posts on local Facebook Coin Groups that talks about this variant.