Vintage antique blue stone w silver grape motif pin or brooch 1.5”

Antique / Vintage brooch in silver w blue stone Old style hinge please zoom in early 1900’s is my thought Blue stone has some colors in very subtle kinds & is only mildly polished. Has patina and it did shine up a bit w slight rubbing I leave as found as some prefer the color variations There is a stamp I can’t quite make it out I do believe this is near antique age. O believe it’s a circle w initials HC or Yc? Please zoom in As seen —fyi As seen in live or as pictured Offers & Bundle welcome Pet friendly Non smokers Display table escapes