Test pieces were struck in 2011 and 2012 in the following combinations using newer Martha Washingon dies than found on J2115-J2126/P2082 combined with a reverse similar in style to the regular issue quarters with both sides showing mottos with reversed or scrambled lettering, etc.
Additional information on this can be found in the "ALTERNATIVE METALS STUDY" submitted to the U.S. Mint by Concurrent Technologies Corporation.
Quarter dies were used to simulate the current cupro-nickel clad, dimes, quarters and half dollars. Tests were also done for cents
and nickels as well.
Examples were struck in the following combinations:
1) Current Cupro-Nickel clad
2) 669z (75Cu-10Zn-5Ni-10Mn) (PMX Industries)
3) Multi-Ply-Plated Steel (Lot #140) (Royal Canadian Mint)
4) Dura-White-Plated Zinc 5́ Sn (Jarden Zinc Products)
5) Dura-White-Plated Zinc 8́ Sn (Jarden Zinc Products)
6) Dura-White-Plated Zinc 10́ Sn (Jarden Zinc Products)
7) Nickel-Plated Steel (aRMour™ 25 ́m Ni on low-carbon steel) (Royal Mint)
8) 302 Stainless Steel (Carpenter Technology)
9) 302 Stainless Steel (Radical Anneal)
The report has images, usually of one side, for all of these combinations. Click on the thumbnail image to see a couple of these. The alloys used have either a steel or a yellowish color.
It is unclear whether or not, the Mint would confiscate these should any turn up in collector's hands.
Photos courtesy of the U.S. Mint.