It is possibly a token rather than a coin. More detail would be helpful.
A thong starts with a T and is a type of clothing...tank toptube toptop hattankinitrousersT-shirtturtlenecktoe sockstightstrousseautoggle coattennis dresstietop coattrench coattuxedotunictailored suittutu
at the top of one's gameat the top of the chartstop dogspin like a topflip one's topon top of the worldwith a cherry on topshout it from the rooftopsmake it to the topTop that one!on top of eachotherat the top of the classtop of the linetop heavya top hatwork from the top downtop 40top 10race at top speedtop brass (informal, meaing the highest ranking people in an organization)on top of the worldand to top it off . . .off the top of one's headat the top of one's lista top priorityto yell at the top of one's lungstop-notchtop jobunder the big topfrom top to bottoma long climb to the toptop qualityJust try and top that!Take it from the top. (meaning the beginning)top-of-the-linego out on topto top off a drink, to top with whipped cream,