TF (in circle) -

Theodor Fahrner, Pforzheim, Germany. 1855 - 1979.

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Fishel - (mark is fish with Sterling written inside - and L)

Fishel, Nessler & Co., New York, NY. 1893 - 1937.

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Florenza -

Dan Kasoff, Inc., New York, NY. Since 1956.

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Francois and Jewels by Francois -

Coro, Inc., New York, NY. Both marks since 1937.

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