Can Anyone Identify This Heart Cancel?

I have looked for this cancel in the following book:

United States Cancellations 1845-1869 (Skinner & Eno)
A Guide to 19th Century United States Postmarks and Cancellations (Kenneth Gilman)
New York Foreign Mail Cancellations (Arthur Van Vlissingen & Morrison Waud)
U. S. Cancels (Sol Salkind)
The Waterbury Cancellations 1865-1890 (Paul Rohloff)
Billig's Philatelic Handbook Vol 33
Cancellations and Killers of the Banknote Era 1870-1894 (James Cole)

I also looked in the Fancy Cancel Database on Stamp Smarter website. So far, I have not found it or anything close. Has anyone seen this cancel before?

Are you sure it's a heart within a square.
Looks uneven if it is a heart?

Most fancy and unusual cancels of this era were hand carved on wood or cork and wore with use.

Assuming the frame is meant to be viewed square-on (ie, with its sides parallel to the edges of the stamp) then it would be a strange angle to depict a heart. For this reason alone, I don't think that's what was intended. Looks more like a big fat lower-case 'r'.

Orientation & description:
I would call this "heart in diamond"

Thanks for the comments. I see it as a heart in a diamond as well. I don't think this was recorded anywhere, but not every fancy cancel has been recorded.