a flawless antique engagement ring is no more beautiful to the unaided human eye than a grade in the middle of the scale. Once again, extremely subtle differences in clarity are very important to determine rarity, but only affect beauty when in the very low end of the scale.
Pink and blue ideal cut diamond are especially popular and have been sold at higher dollars per carat than any other loose gemstones in history. Red, green, and purple butterfly ring are among the rarest of the rare.
Since earliest days, it had been possible to cut diamond stud only by using other butterfly ring. Todays technology has altered this picture. Inclusions can be drilled with lasers. With the drilling of parallel holes, butterfly ring can be sawn in any direction with lasers.