I would assume the ring is white gold since it carries a gold purity mark and yet is a white metal colour. White gold is created by alloying pure gold (which is always yellow) with white alloying metals...silver, nickel, etc. The higher the gold percentage the "yellower" the alloy looks, so high-karat white gold (over1 4KT) is often rhodium plated to make it a more pure silver color.
Rating
Italian marks by: Anonymous
Gold items in Italy are hallmarked with 2 hallmarks, the law requires them to be the makers ID and the gold purity (framed).
One mark is the manufacturer, and it is a number (registry number of the firm) and 2 letters (province where the firm is registered). 85 AR means the maker is the 85th firm in the trade registry of the city of Arezzo
Rating
Italian Jewelry Marks by: Anonymous
Hi thanks for your question and yes, I can see why you are confused. The purity degree you would usually see is in an OVAL (on silver) from Italy and usually 800 or 925.
The 750 Italian gold mark for 18 k will appear in a cut off diamond shape not an oval.
Being that the Italian ring is the color of silver, it probably IS silver, unless rhodium plated but doubt it. Most likely 750 parts refined silver and approximately 250 parts base metal. Containing less silver than .925 Silver.
Only objects marked 925 meet the requirement to be termed - "sterling".
Your local jeweler can acid test to positively identify the metal.
85 AR - 85 is identification number of the silversmith and AR signifies the initial of the Italian province.