There are several “named varieties” of corundum: Ruby, specifically referring to red corundum. Padparadscha is an extremely rare variety of corundum with a pink-orange color. And Sapphire, which actually refers to any color of gem-grade corundum, including the well-known blue, yellow, green, and a rainbow list of others
Lab-Created, or Lab-Crafted Rubies, are chemically and optically identical to a natural Ruby. The difference is that they are grown in artificially perfect conditions in a laboratory instead of uncontrolled within the Earth. Our lab-crafted Rubies are grown using the Czochralski Pulled method which uses a tiny starter crystal of mined Ruby. It is dipped into a solution, and very, very slowly pulled out. The process is so slow, that it only produces Raw Ruby Crystals at a rate of 2mm/hour, but results in a lab-crafted gemstone that has the same optical properties and hardness as its mined counterpart. The brightness of our Ruby is RI 1.76-1.77 – identical to other sapphire colors.
Lab Crafted Ruby Cosmos
The overwhelming majority of real natural mined Rubies at an affordable price range on the market have been “lead-glass filled,” meaning they’ve started out as lower quality Ruby crystals and had a special glass melted into the cracks and fissures to stabilize them, and make them appear more high-quality. But these treated Rubies are much more fragile than untreated Rubies and are considered composites rather than natural gemstones by some Gemologists. Almost all mined Rubies have some level of heat treatment to dissolve the internal inclusions which improve the color and clarity. Some take it a step further and are even diffusion heat treated with Beryllium, which modifies the color by creating a film that penetrates into the stone by about 1mm. This is done with the intent to improve or change the color of the gem. It is incredibly difficult to detect Beryllium diffusion and requires a trained Gemologist with specialized equipment to identify it. Mined Rubies that are unheated or heat-only treated, are by far the most desirable. If you are buying a valuable natural mined Ruby, it’s crucial to have certification or a report from a reputable lab such as GIA. Rubies are one of the most frequently misrepresented and potentially the most difficult to identify compared to other gemstone varieties.
Many Rubies available on the market are synthetic and are not always disclosed as such, so it’s important to be cautious when purchasing Rubies. It’s not unheard of for Rubies to be mislabeled as lab-created when they are actually only a simulated Ruby. This means the gem is made to look like or imitate a Ruby, but doesn’t share the same properties or crystal structure as a true Ruby. The most common gemstone type confused for Ruby is red Spinel, a beautiful gemstone in its own right, but an entirely different gem species. Other less convincing Ruby simulants might include red garnets, red cubic zirconia, or even red glass.