Mohs Scale of Hardness

This blog post is dedicated to Mohs scale of hardness. We use it frequently with our stone of the month series so we wanted to take this opportunity to dedicate an entire post to explain it. It is important to know the Mohs hardness in order to better care for different gemstones.

The Mohs scale is a way of measuring a stone’s scratch resistance against a harder material. It was invented in 1812 by the German geologist and mineralogist Friedrich Mohs and ever since has been used to test and describe the hardness of minerals. While Mohs was the first one to invent an actual scale, testing the hardness of minerals by scratching them against each other was nothing new to people at that point. As a matter of fact, people had been doing it for hundreds of years prior.

The scale goes from 1 being the softest to 10 the hardest. If you have been following our birthstone blog series, then you know that diamonds are the hardest of all minerals, measuring a 10 on the Mohs scale of hardness. The turquoise on the other hand only measures a 5-7 on the Mohs scale of hardness, which makes this stone soft and prone to scratches.

To give you a better idea of how hard a diamond actually is let’s compare it to common objects. For example a fingernail is a 2.5 on the scale, while a copper penny is not much higher with a 3 on the Mohs scale of hardness. Glass on the other hand is already about a 7 on the Mohs scale of hardness, making it about as hard as quartz.

I hope this helped you understand what we are talking about when we get a little bit carried away with all of our jewelry and gemstone talk!

Sapphire – Stone of the Month

The sapphire is often referred to as the ruby‘s sister. Why? Because they are both made out of the same material, the mineral corundum. Gemstones that belong to the corundum family, which are the hardest besides diamonds, consist of pure aluminum oxide, which over many years crystallized into beautiful colorless gemstones. Other elements such as iron and chrome are responsible for the sapphire’s beautiful coloring. The word “sapphire” derives from the Latin “saphirus” and the Greek “sapheiros”, meaning “blue.” Although mostly known for its deep blue color, the sapphire can come in many other colors including red, yellow, green and pink.

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The sapphire dates back to 800 B.C. when they were the gems of choice among clergy and royalty of ancient civilizations like Persia. Blue sapphires were believed to reflect heaven and ward off evil, often put into jewelry as a talisman.

Good quality sapphires are rather rare and are only be found in Burma, India, Sri Lanka, Africa and Brazil. Since the color of the sapphire is so important, and since the stone shines in different colors from different angles, the cutter needs to make sure to cut this very hard gemstone in the right angle in order to maximize the brilliance and luster.
Even though the sapphire is a rather expensive stone to own, once you own it it will be fairly simple to keep clean and beautiful. Due to its hardness the stone doesn’t easily break, and because of its value and mystery, this beautiful gem can be a wonderful substitute for diamonds in engagement rings. It is also associated with 45th wedding anniversaries.

Photo Credit: Flickr.com – dctim1