Opal is the brand name for a cultivar of apple also known as ‘UEB32642’, produced by crossing ‘Golden Delicious’ with ‘Topaz’. Developed by the Institute of Experimental Botany in Prague and FruitSelect in 1999, it is grown by FirstFruits Farms LLC in Washington and marketed by FirstFruits Marketing. The white flesh underneath is crisp and juicy, with a resounding crunch, similar to a Honeycrisp. Flavor-wise, it’s quite sweet and slightly floral. The Opal apple is actually a cross between a Golden Delicious and a Topaz apple, and it’s crisp with a sweet, floral flavor. Plus, it still has all the health benefits that every other apple has. … For tested apple varieties, the flesh still contained about 84 percent of the fruit’s total antioxidant content on average.