According to Three
Graces collector Mark A.
Staal, The Three
Graces and Their Numismatic
Mythology, 2004, the Three
Graces only appeared three times on
Roman imperial coins, twice for
Faustina II and once on a
medallion of
Lucilla.
Your
type of
Faustina II:
Staal knew specimens of this
denarius from Aufhäuser 18, 1989, 420 and Coin Galleries,
Dec. 2001, 2447. He also
had a worn and plugged example himself, which he later sold in
CNG E225, 2010, 359.
Same
type on
aurei: there are two specimens in
CoinArchives Pro, both illustrated below. The first has normal drapery on Faustina's
bust, while the second has the added drapery in front and at back that you observed on your
denarius! I
had never noticed such added drapery on an empress'
bust before, and have no idea how to explain it.
This Three
Graces type on
sestertii:
BMC 959, their online image reproduced below. I also have a specimen, from the same
rev. die as the BM's, but a different
obv. die.
This
type must belong late in Faustina's coinage, since it generally used the same coiffure for her that was also used for her coinage as
Diva, after her death in 175 or 176. However I notice that a
denarius of this
type that I acquired in 2014 has a different, presumably earlier, coiffure, with a wavy strand of hair on top of straight hairs above her forehead and covering her ear, and her bun bound with a band of pearls.