When it comes to buying diamonds as an investment, you might be tempted by a gorgeous, sparkly cluster in the jeweller's window.  But are cluster diamonds a good buy and exactly what are you getting for your cash?  Here's a helpful guide.

Carats and value

Generally speaking, single diamonds with a high carat weight are extremely expensive.  This is because whole, undamaged diamonds are much harder to come by and the processing and polishing process is fraught with difficulty. 

In contrast, cluster diamond rings are made by using lots of very small diamonds, which are set together in a cluster.  These diamonds are usually chips left over from larger stones and are consequently much cheaper than one large diamond.

When you buy a solitaire diamond, you pay for that single stone and the carat weight quoted refers to that.  The carat weight quoted for a cluster of stones refers to the total weight of all the stones combined.   This is why a cluster is always much cheaper than a solitaire.

Aesthetics

Aside from the price, the main difference between solitaire diamonds and clusters is something referred to in the industry as 'light performance'.

Clusters of tiny diamonds really sparkle.  Each stone catches and reflects the light as the wearer moves, creating a magical twinkling effect.  However, solitaires have a much greater surface area, which refracts and disperses light as well as reflecting it.  This means that solitaire diamonds have an almost ethereal quality of inner fire that far out-sparkles even the most extravagant cluster.

Quality

When you purchase a solitaire diamond, the jeweller will be able to tell you exactly what cut, colour and grade of stone you're getting.  However, cluster diamonds are often made-up from a variety of chips and there's no real way of telling anything about their origins.

Cluster diamonds are always sold pre-set.  This means that you have to buy the whole piece, rather than just the stones.  With solitaire diamonds, you have the option of purchasing the individual stone and then choosing the setting that you want for it.  This means that you know the precise value of the diamond, minus the setting.

If you are looking to buy diamonds as an investment, it's probably better to buy a solitaire diamond, with or without a setting.  However, if you want a dazzling piece of beautiful costume jewellery, you could opt to buy the most elaborate cluster that you can afford.  Why not have a chat with jewellers in your area for more advice?