Does size matter?

In short.

YES!

Marketing has successfully made a fair few people desire a 1 carat stone (or bigger) for their engagement ring. This is due to a massive push from the diamond industry but what does that mean when you start talking about coloured stones?

Something that some people don't realise is that different gems have different densities. This will impact the millimetre size/weight when comparing different stones.

For example if the following were all well cut, 6mm round, they would weigh:

Diamond 0.80ct

Sapphire 1.08ct

Emerald 0.72ct

Tanzanite 0.87ct

Peridot 0.90ct

Garnet 1.03ct

Ruby 1.08ct

Two man made gems purely for comparison:

Cubic Zirconia 1.44ct

Moissanite 0.68ct

All the same size but very different weights.

Some random gems for eye candy.

I personally prefer to talk in millimetres when discussing coloured stones purely for clarity. Imagine if you wanted a the look of a 1.50ct diamond ring you saw in a window, but in sapphire. You go to your jeweller and say you want a 1.50ct sapphire... The ring is made and you are presented with a stone visually much smaller than what you were expecting! Disaster!

Another reason size does matter - Price.

There are a lot of factors that determine the value of a coloured stone. I will just touch on one of the many here or this post will be WAY too long.

One factor a causal jewellery shopper would never give two thoughts to is HOW the crystal grows.

What crystal system it belongs to and the environment it forms in has a massive impact on its final price.

Peridot is a great example. It is very reasonably priced in small stones, then between calibrated sizes, the cost almost quadruples! This is due to the unstable environment in which peridot is found.

Formed in magma and forced to the surface by volcanic activity or violent tectonic movement, larger crystals are extremely rare. They either don't have a chance to grow large enough to cut into a big beautiful gemstone or the crystal gets damaged in its journey to the surface. In this instance its rarity coming into play.

As for the crystal system itself. The shape of the crystal, in its rough form, determines what sizes and shapes can be cut from them. If there is heavy wastage in cutting your desired shape again the price will jump.

I will leave this post here as I can feel myself starting to waffle.

Hope this has given some food for thought and didn't get too far off track!