There are quite a number of saints named Isabelle or Isabella so you need to narrow your question down to one of them.
St. Isabelle of France spoke one of the many dialects of Old French.
Isabelle Evesson was born in 1870, in St. Louis, Missouri, USA.
February 26
St. Jude Medical has ticker symbol 'STJ'.
The symbol for St. Joe Company (The) in the NYSE is: JOE.
Maximilian Kolbe has no symbol.
Maximilian Kolbe has no symbol.
Isabelle Wackernagel has written: 'An analysis between Basle and St. E tienne ribbon industry with a focus on Basle during the period of 1850-1930'
Clovers.
Clovers.
a gridiron
None - yet. However - it has been suggested that 'St' should be used for either Antimony (current symbol Sb) or Tin (current symbol Sn).