By comparison, "non-proprietary" cuts or "generic" cuts are the common ones that have sold for years. An example of a patented cut is Tiffany Lucida and an example of a diamond with a registered trademark is Hearts on Fire, which is not patentable because it is a generic round-brilliant cut.
Cut patents are very costly. An outlay of hundreds of thousands of dollars for protection in the US, some European and the main diamond cutting nations (Israel and India) is common. This is thought to be enough to deter copycats from manufacturing "me-too" cuts for smaller countries.
There were about 95 US patents for new cuts during the last century, but this figure has soared in the past nine years, with more than 245 new patent cuts registered.
This reflects De Beers Supplier of Choice policy from around the turn of the century, linking sightholders' ongoing supply of rough diamonds to attempts to brand and add value to diamonds.
De Beers told its sightholders to market "downstream" to retailers and consumers and, for many diamond manufacturers who had only ever cut generic rounds and princess cuts, one way to achieve guaranteed supply was to launch and market unique diamond cuts.
Copyright, which is a free, common-law intellectual property right, has not been accepted by courts as applicable to diamond designs. The US Copyright Office maintained "that gemstone faceting was a non-copyrightable array of common geometrical shapes in a three-dimensional object".
In 2000, however, the office granted the first copyright registration for a gemstone design to the Elara - a square cut-cornered brilliant design.
So why proprietary or branded cuts? Well, they can make more money. Many new cuts are simply ways to create a good-looking diamond that gets a better yield from each piece of rough diamond.
There are other companies that are prepared to accept a smaller carat weight yield for a better looking diamond that will "sell itself"; so the company will get a higher price per carat.
Retailers deciding whether or not to invest in a specific product range have much to consider.
Sometimes the marketing plan is enough and the diamond itself is of no great importance.
Patented diamond Cut X will spend $1 million a year advertising nationally and one's store's name will be listed on every advertisement. But if the diamond looks dead and customers do not buy, then the retailer is left with dead stock, and the brand will not tolerate deep discounting.
The problem is when the retailer sees the range at a trade fair, the best is often on display; but the main criteria for producing these diamonds becomes yield and ROI and the goods delivered are not a patch on those at the show.
Retailers should establish some means to ensure they get what they want. One way is to request or buy a stone sample as a "master stone". Or use cut grading tools like the Hearts and Arrows viewers, Ideal-Scope and ASET scopes.
A benefit for retailers can be stock rotation and a wider range of carat weights, clarity and colours held in stock by the wholesaler as well as co-operative advertising.
Make sure that any proprietary diamonds in store are trademark protected. Relying on common law as protection can be very messy if there is another company selling a diamond by the same name.