1.66ct D SI1 Radiant Natural Diamond

About this 1.66ct natural radiant diamond

This 1.66ct natural radiant sits in the one-and-a-half to two carat band, graded D colour (colourless) and SI1 clarity (slightly-included), with a standard cut grade stated by the retailer rather than the lab and certified by GIA 6197678456. Listed at 5 retailers as of October 31, 2026, with a relatively tight 9% spread, which is unusual at this carat range and suggests competitive pricing across the listings. Cut grade matters more than carat or clarity for visible brilliance. If you can shift budget toward an Excellent or Ideal cut, do it before chasing higher colour or clarity.