'Real Housewives' Jill Zarin -- Check Out My $19,000 Ring ... Courtesy of Elizabeth Taylor

Former "Real Housewives of NYC" star Jill Zarin ain't bitter she got the boot from the show -- telling TMZ, she's still got a filthy rich husband ... and she proved it by flashing the $19,000 ring he bought her last month at Elizabeth Taylor's jewelry collection.

Honestly, we have no idea how she walked around with that thing last night in New York -- because it's freaking MASSIVE ... a gemstone the size of a baby's fist, designed by famed jeweler Zohrab Istanboulian, and once worn by Liz Taylor herself.

The ET auction took place last month in NYC -- and you may recall ... rich people of all shapes and sizes were at each other's throats to get their grubby mitts on the late legend's bling.