Inside Look: Gem Sourcing

| 5 min read

We’re often asked how Gemporia go about buying gemstones and making sure you’re getting the best deals. With such a wide variety of nature's gems discovered in so many different countries, there is, in fact, not one way, but a multitude of different ways in which we source our gems.

So, let's have a look at the similarities when sourcing gemstones. Firstly, it does not matter what country you are in, or what gem you are buying, business is always transacted in American dollars.

Secondly, every single gem parcel we buy, even if we have bought the rough direct from the mine, is sent to a government managed gem laboratory for testing. Even though mistakes are rare, we have occasionally had incidents where the gems were not as disclosed by the seller. Also, in a couple of parcels from alluvial deposits, where several different gem types are discovered in the same river bed, the miner has accidentally misidentified similar looking gems. In their rough state, it's hard for example to tell a Spinel from a Ruby. But through a combination of our own thorough testing, all backed up by an expertly run external laboratory, we are able to give a lifetime guarantee that the gems we sell are as stated on the authenticity cards that ultimately ships with each piece of jewellery.

Believe it or not, these things are the only similarities across all of the gems we source. From here on in, everything changes based on the gemstone. It varies country by country. It also varies depending on whether we are buying rough that we will later cut ourselves or buying gems already cut and polished by others.

Let's look at what happens when we buy parcels of gems that are already cut. Firstly, we always refer to them as parcels. Whether it's just a few carats or tens of thousands of carats, they are always described as parcels.

Sourcing gemstones at the recent Hong Kong Gem Show

Parcels are normally divided by gem type, gem shape and size. If we are buying cut gems, we normally evaluate all of the parcels first and then offer an average price per carat for the deal. In the gem trade, each deal is always negotiated by arriving at an average price per carat that the seller is prepared to accept and the buyer is prepared to pay. With the focus being on price per carat, you begin to understand why most cutting houses try and maximize the carat weight they can produce from the rough.

"In the gem trade, each deal is always negotiated by arriving at an average price per carat that the seller is prepared to accept and the buyer is prepared to pay."

What we try and do at Gemporia is to agree on a price per carat, but also agree a percentage of the parcel that we can return after our experts have made a more thorough examination. Once we have decided what gems we are buying and which we are returning to the supplier, it's time to grade the gems. At this stage the supplier will have already divided the overall parcels by size and shape and if it's a large deal, may have already further separated by depth of tone. Let's imagine we are looking at a parcel of 6x4mm oval Tanzanites and let's say there were 80 pieces in total. In an ideal world you would not have to further divide the parcel. The bigger the parcel the more flexibility it gives the jewellery designer in terms of how many pieces they can produce. Frustratingly, in an attempt to only create the finest jewellery, normally the parcels get divided into many smaller sub parcels. Due to different shades and differing clarities it's not uncommon to see parcels divided a further 10 or 15 times.

At this stage, the individual details of each sub parcel are entered into our database. As well as the quantity, we enter the size, carat weight, tone, saturation and clarity. We also allocate the cost price. Now this might sound like a simple task, but actually it's often frustratingly challenging. Let's assume we paid $30 per piece and that we bought 80 pieces. We then further divided this parcel into three sub parcels, one with a deep tone, one with a medium tone and one with a lighter tone. Rather than entering them all into the system at $30, we will add a different value to each bag. As long as the sum of each bag ends up at the same total value, the accountants are happy.

At this point the designers can now gain access to the database. Let's say one of the sub parcels had a quantity of 30 pieces and the designer decides to make a trilogy ring with the gems. The next step is for the gem sorting team to once more go through the parcel, but this time, they are trying to find which three gems are the closest match. This is often referred to as colour matching, but is far more than that. Here the gem sorter has to further evaluate surface lustre, clarity and of course, tone and saturation. It can be difficult work trying to match the stones, which to the untrained eye can look identical. Once completed, the gems are now bagged individually and sent to the gem setter, to be painstakingly set into a beautiful piece of jewellery.

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