This is an exceptional large, clean, blue, cushion-cut zircon from Cambodia. Weighing in at 36.11 carats, this zircon is quite a large specimen, as most blue zircon are found under 5 carats; over 10 carats is quite rare for this type of color. Not only is the size impressive but the color hits the sweet spot for zircon. The swimming-pool blue is reminiscent of a fine paraiba and invites you to dive in. Blues of this size are often too dark or off-color. The strong doubling shows up more in the photo than in hand, but it's a good optical tool to identify zircon.