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 top-tier cut grade stated by the retailer rather than the lab and certified by GIA 6552974932. Listed at 22 retailers as of October 29, 2026, with a 143% spread between the cheapest and most expensive listing. That is exactly the kind of price-discovery gap Carat Hunter was built to surface. SI-grade stones are eye-clean roughly 60 to 70% of the time at this carat range. Check the inclusion plot on the cert and ask the retailer for high-resolution video before buying.