A classic 1930s engagement/solitaire ring featuring a rare type II A old-cut diamond weighing 5.59 cts, of I colour and VS1 clarity (certificate available). Smaller diamonds along half the band to enhance the fine platinum mounting. The stone is sellable also loose. Type IIa diamonds make up 1–2% of all natural diamonds (1.8% of gem diamonds). These diamonds are almost or entirely devoid of impurities, and consequently are usually colorless and have the highest thermal conductivity. They are very transparent in ultraviolet, down to 230 nm. Many famous large diamonds, like the Cullinan, Koh-i-Noor, and Lesedi La Rona, are Type IIa.