Emigre's beautiful Priori has them in both serif and sans.

A number of Venetian revivals, including Jenson Classico, Iowan Old Style.

Some of the Old English fonts, like Collins. Hefeweizen. Generation Uncial. ITC Korigan (ok, so it's a kinda squashy diamond). Jester.

ITC Zapf Chancery. Clairvaux. Our very own Hrant's Cristaal.

A few more lineales, probably inspired by Kabel: Fedra Sans (and Fedra Mono and Serif). Albe Sans.

Hope this helps.

Ondine and many other uncials (you'll have to scroll a bit to find them.)

Baker Signet

As any Londoner must surely notice on a daily basis, Johnston's Underground lettering has such an �i�.

(Of course what we really see is New Johnston, which is much more thoroughgoing in its use of the diamond motif. Those who enjoy reading other people's style guides -- surely I'm not the only one? -- will find much to entertain them here.)

Dorothea
Hiroshige
Horley Old Style
CG Signature
Tiepolo
Adderville
Argus

Jante Antiqua by Poul S�gren

Call off the hounds !
I wish I could send you all a little something from Tiffany's, instead I can only offer heartfelt thoughts of gratitude to all of you whom have assisted in my search. Big hugs and, again, thank you one and all. Geo.

Well considering the title of this thread, I expected at least a small diamond by way of thanks.