Star Sapphires and Rubies

Commonly known as ruby star and sapphire star but they also appear in garnet, spinel and other less known varieties. There are differences between all stars, but we will here pretend that nature made all stars equal.

Gemstone phenomena, especially asterism, are a tough call to judge on photo. However, no normal jeweler will be able to show you a fine natural star sapphire, let alone a selection to choose from. Good stars are rare even beyond the normal gemstone rarity. Unless you live in a metropolis or travel to Tucson or Basel, the internet is the only place to compare and buy such gems.

Looking at images on the web, stars seem to be quite an ugly bunch. Rarely do they show nice colors, often they are zoned, patchy, heavily included, silky, egg-shaped and at times the asterism is hardly visible at all.

And of course you will find many "perfect", "fully colored", giant star sapphires or rubies for a few dollars. These are synthetic or surface diffused or lead-glass filled gems which are mostly worth just as much as they cost.

There is nothing wrong with twenty carat Linde star for fifty dollar, but be wary of those sellers trying to offer them as real.

So, are they are either ugly or faked? No, don't be discouraged. Real, natural stars are mind-shaking and heart-breaking. Many star skeptics have become sworn star fans after their first encounter with fine quality. 

Here is what to look for when selecting a star sapphire or ruby online:

The value of any star sapphire ring depends strongly on the quality of its asterism, which is defined by (no order):

  1. Sharpness

  2. Symmetry & linearity

  3. Completeness (6 rays mostly)
  4. Travel (smoothness of movement)
  5. Position
  6. Lucidity & Depth 

The relative importance of these criteria are questions of personal taste, culture and fashion. Most collectors would perhaps trade in some off-centeredness for good movement, or overlook a meandering leg while frowning at a missing one. 

We feel lucidity, travel, position and completeness may be most important and price relevant.

Only then, with decreasing relevance, come:

  1. Color

  2. Clarity (inclusions)

  3. Shape
  4. Finish (top and bottom) 

Asterism and color together easily make up 80% of the value of a star (sapphire, ruby or any other variety).

With ten dimensions (as compared to the old 4 Cs) stars are a quite demanding topic. But they are rewarding, too.