Most people know a few things about diamonds. Some of these more well-known facts are that diamonds are the hardest natural substance there is, that they can cut glass, that they come from deep within the earth, and that they’re beautiful, of course. But how much do you know about the different shapes, or cuts, of diamonds? Here are 7 surprising facts about diamond shapes that you’ve probably never heard:

1. The cut of a diamond is widely considered to be the gem’s most important characteristic, as the way it is cut determines the diamond’s brilliance and fire. When a diamond is cut, the gemcutter carefully considers which cut will allow the most light to enter the stone. The more light that can enter, the more brilliant, magnificent and, consequently, valuable the finished product will be.

2. There are three main categories of diamond shapes: brilliant cuts, step cuts, and mixed cuts. Brilliant cuts are those that allow for the best light reflection, resulting in a more brilliant gem. Step cuts, such as the emerald and baguette, feature stacked facets that resemble stairs, and mixed cuts are a combination of brilliant and step cuts.

3. The practice of shaping diamonds is believed to date back to the 13th century, where there is evidence that medieval Islamic gemcutters shaped diamonds into simple table cuts. However, diamond cutting as we know it today did not occur until the 16th century, when advancements in equipment allowed European gemcutters to facet diamonds rather than just polish them.

4. The most popular and enduring diamond cut is the round brilliant, which features multiple facets for enhanced brilliance. This cut was first developed in 1919, and was met with immediate adoration. Since then, gemcutters have relied on mathematical calculations and light behaviour theories to make cuts that maximize brilliance and fire and bring out each stone’s unique qualities.

5. The brilliant cut diamond is also the most hardy of all the diamond cuts. Its round shape lends it impressive durability, along with making it less likely to chip, crack or break as there are no edges or corners to snag or bang.

6. Pear cut diamonds are a hybrid of the oval and marquise cut, resembling a teardrop in shape.  Pear shaped diamonds are another notable cut, but they’re not quite as common as the round brilliant or some of the other more popular cuts. Perfect for pendants and other delicate jewellery pieces, the pear cut is difficult to master and takes gemcutters many years of practice to perfect. Fun fact: the largest cut diamond in the world, The Star of Africa, is pear cut.

7. Different diamond shapes have different meanings. Round diamonds represent unending love, while oval diamonds are regarded as fertility charms, likely because of their resemblance to an egg. Emerald cut gems evoke elegance, clarity and openness, and marquise diamonds, with a cut designed to make the gem appear larger than it is, are said to be representative of opulence and extravagance.