The gemstone is ruby colored glass. I had a jeweler examine this ring. It is an 18K Gold ring with colored glass. Origin: Italy. The practice of setting a glass gemstone is not unusual in Italy. Size: 7.75 US. Please see photo of measurement. Italian 18K Gold Jewelry is marked with “750.” Condition very good Marquise cut ruby coloured gemstone. Gemstone has not been identified. Cushion cutting to pavilion. Italian hallmark for 18ct gold and region mark is Alessandria. Italian Maker reg mark is 515. Also stamped 750. Pavilion facet sits against finger. All photos show the exact item for sale. Vintage Item. May need some clean- up to look its best…but it’s already gorgeous! Note: Poshmark authenticates items that sell for $500 & up. Offers considered. Bundle to save more. Questions? Please leave a comment below.