Vintage Lighthouse Lens Purple Gemstone Gold-Plated Ring Size 6

This is a showstopper of a ring! It's a vintage piece from the 1980s, featuring a lighthouse lens cut faux purple gemstone (tests as glass with a Presidium Gem Tester II). The band is 18K GE, and it is signed, but I'm unable to identify the maker. it's in excellent condition, it's a size 6, and it will come in a ring box.