According to this article the average size for a diamond is 0.9 carat, but as we all know, there are several ways of measuring 'averages'. I would say that an independent jeweller who sells a 1 carat ring would consider it a good day. My hunch is that most people buy a diamond ring which is between 0.25 and 0.75 carat, although I don't have the data to back that up yet.
Anyway, if you fancy making an impression with your proposal then a 1 carat diamond is certainly worth considering. When I proposed six years ago, a 1 carat ring was well out of my price range, but things have changed a bit in recent years with many more online jewellers offering very low prices and a busy second hand diamond market.
We compared more than thirty diamonds with a 1 carat grading and found prices ranging from £370 up to £7500. A later study we did looking at expensive diamond rings found many 1 carat rings costing well over £10,000 but for our first price comparison we just looked for the cheapest available on each website, regardless of quality.
The cheapest 1 carat ring of them all was (unsurprisingly) a second hand 1 carat diamond. In this case, it was an eBay seller but no doubt you could find similar deals on other second hand sites. The advantage of eBay is that they offer more buyer protection than some, so if you end up paying £370 for a Haribo ring then you can get your money back.
If we exclude second hand rings, then the cheapest 1 carat diamond ring we found was just over £700 from Overstock. It was a relatively low grade (H-I colour, I1 – I2 clarity, 14 carat white gold) but that's still a very low price for a diamond of that carat.
The sizeable caveat with that is that Overstock is based in the USA. Whilst that price in included the import duties and taxes, it is worth realising that it will take a bit of time to arrive and even longer if you need to send it back.
For me, buying from abroad is too much hassle, but it certainly becomes more appealing when you start looking at larger carat diamonds (see this blog on importing diamonds for more on that topic).
So, if you want to buy a 1 carat diamond and you want to avoid a) second hand buyers and b) non-UK based jewellers, which is your cheapest option?
The answer is Amazon, or Amazon Marketplace to be precise which is a third party seller operating through Amazon. We found a 1 carat diamond ring selling for just over £800. It's worth saying though that the clarity was pretty poor (I3) and you will start to notice differences in quality more on a larger carat diamond than you might in a smaller carat diamond.
And what if you'd like to buy from a high street jeweller, either because you want the convenience of easy returns to store, or because you like the prestige of a ring which came from a well known jeweller?
The cheapest in our comparison was F Hinds at £1999. Clarity and colour wasn't specified, so we can assume it is a lower grade diamond, but it was 18 carat gold which is one of the more expensive metals for a diamond setting.
You can see the full 1 carat diamond price comparison here.
I hope she says yes...