R12495 | medium | right | play | “Ruby ID: R12495 Carat Weight: 1.04ct Origin: Mozambique” While auction houses will tell you that Burmese rubies are the best, the best rubies are ones that are vividly colored, visibly clear, and well-cut. In short, three of the 4Cs. Carat weight isn’t mentioned here because it is an evaluation of overall rarity rather than quality.
Geographical origin has little to do with the quality of individual rubies since no source produces a single color of rubies. All sources produce a range of colors and qualities, many of which overlap with different sources. Myanmar (better known as Burma) and Mozambique have the highest yields of top quality ruby yields in the whole world, but places like Madagascar can produce incredible specimens too.
Even with expensive equipment and trained professionals, gemological laboratories are often unable to determine the exact origin of rubies and other gems. The origins might be listed as undetermined or give a geographical estimate depending on individual lab practices.
Orangish Red
Purplish Red
Pinkish Red
Given all these factors, the most popular rubies are usually ones that are an unmodified red. However, other colors of rubies are widely available too and at a more accommodating price range. It also depends on the person buying the ruby; not everyone likes a pure, deep red. My own favorite color of rubies is pinkish red rather than the intense, pure red that most people like.
Same brilliant cut, different shapes
Brilliant Cut, Round
R12251
Ruby ID: R12251
Weight: 0.52 carats
Origin: Myanmar (formerly Burma)
Brilliant Cut, Oval
R12332
Ruby ID: R12332
Weight: 0.46 carats
Origin: Thailand (formerly Siam)
Ideally, a ruby will appear completely transparent without magnification. Magnification will show inclusions, however these inclusions are how gemologists determine synthetic versus natural gems, treatments, and sometimes gem origin.
Note, cut should not be confused with shape since they are two separate factors. Cut refers to the arrangement of the facets on a gem, while shape specifically refers to the overall form.
What denotes a quality cut is symmetry, with the directions varying based on shape. A round cut should be symmetrical around the full circumference of a circle. A pear shape on the other hand will only have mirrored symmetry in one direction.
Unfortunately, cutting gems usually results in a large loss of carat weight ranging from 50 to 70 percent of the rough gem. Rarely is higher carat weight retention achieved. Because of how great the loss of carat weight can be (and subsequent loss of a piece of the cutter’s paycheck). The cut is usually slightly off in order to preserve carat weight and/or show the best color and clarity.
Different cuts, same shape
Step Cut, Square
R10186
Ruby ID: R10186
Weight: 1.04 carats
Origin: Mozambique
Brilliant Cut, Square
R12363
Ruby ID: R12363
Weight: 0.34 carats
Origin: Myanmar (formerly Burma)