0.51ct E SI1 Marquise Natural Diamond

About this 0.51ct natural marquise diamond

This 0.51ct natural marquise sits in the half to three-quarter carat band, graded E colour (colourless) and SI1 clarity (slightly-included), with a standard cut grade stated by the retailer rather than the lab and certified by GIA 2508270359. Listed at 22 retailers as of October 30, 2026, with a 324% spread between the cheapest and most expensive listing. That is exactly the kind of price-discovery gap Carat Hunter was built to surface. 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.