Technically the rarest and most desirable rubies are those that are faceted, but rubies that have been polished into cabochon shapes have their own appeal. Cabochon cuts show amazing color purity with no extinction . Their potential cuts are not as varied as faceted or carved ones, but there are a few styles. R9999 | medium | play | right | “Ruby ID: R9999 – Weight: 2.20 – Origin: Mozambique”
A basic cabochon cut is defined by having a domed top. Ruby cabochons will typically have a curved bottom too, but that isn’t necessarily the rule. The curves can be adjusted in many ways, but usually stick to a side profile like the example below.
One of the most desirable and unique cabochon cuts is the sugarloaf. This cut is defined by a shallowly curved base and four sides that are polished to come up in a rounded point. The gem material can occasionally be exceptionally clear, and show-off a very unique appearance. R10044 | right| medium | play | “Ruby ID: R10044 – Weight: 1.91 Carats – Origin: Mozambique”
The term mixed-cut is not exclusive to any type of cut, since it specifically refers to mixing different types of cuts. As an example, a mixed cut gem could have the top be an oval cut with a sugarloaf-like cut on the bottom.
R10044 on the right is an example of a more unusual cut.
R2744 | play | left | medium | “Ruby ID: R2744 – Weight: 1.58 Carats – Origin: Myanmar (formerly Burma)”Cabochon cuts are typically done to either show a ruby’s star, or to be gentler on fractures inside the ruby during cutting and polishing. Cutting a gem is a very brutal process, which is why only very clear rubies get faceted and more experienced cutters are desirable. If there are too many cracks, the gem won’t be able to withstand polishing. If the cutter is not very careful of how they work, the gem they are polishing can shatter on the wheel.
This list of cabochon cuts is by no means a definitive one. New designs are being developed and implemented all the time.