The popularity of these rings grew when Prince William proposed to his girlfriend, Kate Middleton by gifting a cluster ring to her on their engagement day. Several customers and couples believe that the Royal Britain family was the first ones to use diamond cluster rings as engagement rings but it is not entirely true. Most of the diamond cluster rings available in the market contains a primary diamond right in the center. The center stone in these diamond rings is usually covered by a circular halo of smaller diamonds. Any ring that features a halo of smaller diamonds can be classified under the category of cluster diamond rings. However, as per traditions, diamond rings whose outer pattern is exactly in the shape of the smaller diamonds in the ring are considered as diamond cluster rings. If you and your loved one wish to make a bold and unique statement with your diamond engagement ring, and if you want the ring to last a lifetime, then you should consider investing in diamond cluster engagement rings.