The birthstone for July is the ruby. We're taking a closer look at this exquisite red gemstone and revealing our top 10 interesting facts about rubies.
1. Rubies are made of corundum - the exact same mineral as sapphires. This essentially means that rubies are red sapphires. However, unlike sapphires which display almost every colour of the rainbow, rubies only appear in shades of red.
2. The ruby is a traditional gift for the 15th and 40th wedding anniversaries.
3. Ruby gets its luscious red colour from the presence of chromium.
4. A key source for rubies includes the Mogok valley in Myanmar (Burma). According to the American Gem Society Burmese Rubies 'command a premium over brownish or orange-tinged varieties from other regions.' Burmese rubies are also known as pigeon's blood rubies.
5. According to the Gemmological Institute of America, rubies sell for one of the highest prices among coloured gemstones.
6. The word 'ruby' comes from the Latin word for red, 'ruber'.
7. Historically rubies were mistaken for red spinel, a less valuable non-precious gemstone. The Black Prince's ruby was mistaken for a spinel stone. However, in the 19th century the difference between red spinel and genuine rubies was established.
8. Rubies score 9 on Moh's scale of hardness, meaning it's the second hardest natural gemstone after diamond. This makes rubies highly durable and perfect for everyday wear on an engagement ring or other piece of jewellery.
9. Aside from being adorned on jewellery, rubies are also used in watchmaking. Rubies are used in watches to prevent wear and tear of the pivots and bearings. However, today synthetic rubies are more likely to be used in watchmaking.
10. In February 2009, a Myanmar ruby sold for a record-breaking price at Christie's in St. Moritz. The 8.62 carat cushion-shaped ruby fetched an eyewatering $425,000 per carat. However, in 2015 this record was trumped by the 'Sunrise Ruby'.