How To Identify Ruby From A Crystal Shop

For hundreds of years, all red gemstones were considered rubies. Nowadays, we know that's not the case, and today we're going to teach you how to spot a ruby in its rough form as well as in its final faceted form. We'll also go over the key differences between ruby and some of its copycats. Let's get into it!

Ruby Properties

Stones can exhibit different properties in their rough and faceted forms, so let's start with rough material.

Ruby famously occurs in Myanmar, Sri Lanka, Vietnam, and Thailand, among other places. If you happen to find yourself in one of these corners of the world, be on the lookout for red pebbles on riverbanks and gravel deposits. That's where ruby is typically found in alluvial deposits.

These are surface-level gatherings of stones that have been eroded out of the host rock and carried on down a stream until they come to rest. Because ruby is so hard (a nine on the Mohs scale), it survives this rough journey amazingly, and often times, these rough rubies will appear as river-worn stones.

How To Identify Real Ruby?

Now, let's say you're in a crystal shop, and someone is trying to sell you a rough ruby crystal. What do you look for to make sure that ruby is really a ruby?

Let's start with the obvious: its color. While many stones are red, ruby has a unique deep and bright hue that's different from, say, red spinel or garnet. Just take a look at them side by side, and you'll see what I mean.

Ruby tends to be more bright red or purplish-brownish and even pinkish-red. Garnets tend to be a darker red than ruby, and spinels are usually much cleaner than ruby, making them more fiery.

At times, it may take some practice, but the more rubies you see, the more familiar you'll become with their distinct red glow. If you're not so confident in your eye for color, don't worry, there are other ways to spot a ruby.

Shape

Let's talk about their shape. Rubies are part of the trigonal crystal system and can display a number of crystal habits. Some common ones to look out for are prismatic and tabular forms as well as bipyramids. They should be six-sided, as the trigonal system is fairly orderly.

The tabular form can often have triangular growth marks on their surface and striations on the sides. Bipyramids and barrel-shaped crystals can also sport these parallel lines.

Ruby can also feature hexagonal zones of color within the stone, and the surface of even a rough stone should have a bright vitreous luster in some places due in part to ruby's hardness.

Whether it's a cabochon or a faceted stone, here are some things to look out for with cut rubies. Rubies are a 9 on the Mohs scale, meaning they're exceptionally hard. This means that the facet edges of a ruby are going to be sharp and clean and usually free of any dinks or chips. This is where a jeweler's loop is your best friend, revealing things that may not be totally obvious to the naked eye, like the facet edges.

The faces of the stone should also be blemish and scratch-free. If a stone is overly scratched, it may be glass, which is much softer than ruby. If the facet edges are badly chipped or slightly rounded, and there are a bunch of bubbles on the inside, you can bet it's glass.

I should mention that ruby tends to be included, and some of these inclusions can be pretty good indicators that what you're looking at is, in fact, a ruby. You can have inclusions of different crystals inside the body of a ruby.

Inclusions

Needle-like inclusions of a mineral called rutile are also fairly common. In fact, if you have enough of these rutile needles, and if they're oriented properly, you get what's known as a star ruby, a truly exceptional stone that has to be seen to be believed.

See, inclusions aren't always bad. You can also have two-phase inclusions, which is an inclusion in two different phases of matter, usually a liquid and a gas. Imagine a bubble level but trapped inside a natural gemstone. You can also see needles of another mineral, boamite.

Up until this point, all these indicators and clues can pretty much be identified with just a 10x loop and with your widths, but there are still other tests we can do. While it's common to bring a loop to a gem store or a trade show, these other tools are a little less common.