CREATE TABLE table_42670 ("Benchmark" TEXT, "Crown height" TEXT, "Pavilion depth" TEXT, "Table diameter" TEXT, "Girdle thickness" TEXT, "Crown angle" TEXT, "Pavilion angle" TEXT, "Brilliance Grade" TEXT)

Which Brilliance Grade has a Benchmark of practical fine cut?
SELECT "Brilliance Grade" FROM table_42670 WHERE "Benchmark" = 'practical fine cut'
SELECT "Brilliance Grade" FROM "table_42670" WHERE "Benchmark" = 'practical fine cut'