While to the untrained eye, garnets and rubies are very similar stones. However, they each come with vastly different properties. While garnets have become popular in the lower end of the market, rubies hold several key advantages over their less expensive counterparts.
How Rubies and Garnets Are Formed
Those looking for Australian ruby jewellery will be pleased to learn that both rubies and garnets can be found in abundance in Australia, because the Australian continental plate is rich in many types of minerals. Depending on who you ask, the continental plate that Australia sits on is either the same plate or very closely related to the plate on which India is situated—another place where rubies are found in abundance.
While both rubies and garnets are formed the same way as most gems—which is to say heat, pressure, and time in specific geologic conditions—their physical properties are quite different.
Garnets are formed from silicate-rich soils and minerals. Depending on other metal elements present when formation happens, garnets may form into a variety of colours.
Rubies, on the other hand, are formed from soils that contain concentrated amounts of aluminium. When the aluminium oxidises it forms corundum, which, in the presence of chromium, creates the distinctive red hue that rubies are famous for.
Colour and Clarity
While many people believe that garnets only come in red, this colour is simply the most common variety found in nature. Garnets actually come in several colours, including various shades of green, orange, yellow, and even blues and purples. The colour of the garnet is dependent on which minerals and metals are present when it forms.
Conversely, rubies are exclusively red, though the hue may differ slightly across the red spectrum, sometimes approaching an orange colouring. This is a result of each ruby’s unique components.
There is a false belief that because rubies are typically less scintillating than garnets, they are less desirable. This couldn’t be further from the truth. While garnets are typically “cleaner” looking, meaning you can see through them much the same way you can a diamond, inclusions (imperfections) are found throughout rubies.
These imperfections are what give rubies their appeal and are characteristics of each stone’s uniqueness. A garnet will shine like a diamond, causing a rainbow effect as light bounces off the surface; a ruby will absorb all visible spectrums of light except red. This means that red is the only colour that you’ll see when looking at a ruby under bright light conditions. Rubies stand out, especially when combined with other gems such as diamonds, but the sparkle of a garnet may fight for your attention when placed next to a similarly shimmering stone.
While top-quality garnets are more valuable than low-quality rubies, rubies are generally two to three times as valuable as garnets. This difference in value is further widened when it comes to larger stones, as rubies above one carat are exceptionally rare and therefore come with a significantly higher value than even high-quality garnets of similar size.
Rubies being the birthstone for the month of July has long made them a favourite among those born in the heart of the summer months. Thanks to its popularity and rarity when compared to its more common cousin the garnet, the ruby still reigns supreme in the eyes of those looking for a gemstone of exceptional quality.