Understanding the Mohs Scale of Hardness
Not all gemstones were created equally, or with the same hardness and toughness. Understanding how the Mohs Scale comes into play when choosing your center stone or which gems to wear as jewelry is incredibly important.
What is the Mohs Scale of Hardness?
According to the Gemological Institute of America (GIA), the Mohs Scale measures the hardness of gems and minerals based on their resistance to scratching. This is determined by testing how a mineral reacts to contact with a sharp point or other minerals with known hardness on the scale.
The Mohs scale rates hardness from 1-10, with 10 being the hardest. For example, a diamond is a 10/10 and is known to be the hardest mineral on earth. Talc is 1, making it one of the softest.
What is Gemstone Durability/Hardness?
One might think that hardness and toughness are the same thing, but when it comes to gemstones, this is not the case. Additionally, another concept is stability.
Hardness: The hardness measures the gemstone’s resistance to scratching. Scratch resistance tendencies reveal how well a stone reacts to wear and tear, how it can be best cut and faceted, and which setting is the most suitable. Hardness also directly relates to the gemstone’s durability.
Toughness: Hardness and durability are not the same as toughness. Toughness can be defined by how well a gem can withstand resistance to breaking, chipping, and cracking upon impact. Gemstones that rank high on the Mohs scale of hardness can still break, chip, or crack depending on how they are handled.
Stability: Stability refers to a gemstone’s ability to resist damage or changes when exposed to heat, light, or chemicals. If a stone has higher stability (diamond), it can withstand being exposed to these elements, thus making it more durable. Others, such as opal (crystalline gem mineral) are not as stable and may become damaged by intense light.
How is the Scratch Test Performed?
A mineral’s hardness is determined by scratching it against another substance of known hardness listed on the Mohs scale.
A Mohs scratch test can be performed at home by following these steps:
Step 1: Find a flat, clean, flat surface to work on.
Step 2: Gather some easy-to-find specimens that can be used for scratching. These can include quartz (9), steel (7), glass (6), a penny (3), or a fingernail (2.5). If the object is harder, it will scratch the surface of these specimens. If it is softer, the opposite will occur.
Step 3: Examine the surface of both objects for scratches or damage. These observations can provide clues and offer insight into the stone’s identity, narrowing down the possibilities.
*It is important to note that other tests must be performed to accurately confirm the identification of any gemstone.
Is the Mohs Scale of Hardness Equal?
Even though the Mohs scale of hardness rates minerals 1-10 and the numbers are spaced evenly, this does not mean the difference between the ratings is equal.
For example, diamonds are ranked at 10, only one spot above corundum which is ranked at 9. However, diamonds are actually 4x harder than corundum.
Which Stones are Best for Engagement Rings?
The divide between “hard” and “soft” gemstones lies around 7 on the Mohs scale. Stones that rate 7 on the Mohs scale are considered suitable for engagement rings because they can withstand normal wear and tear.
At Lauren B, we advise opting for a gemstone with an 8 or higher rating for your engagement ring center stone. Choosing something that is rated 8 or higher on the Mohs scale ensures that your center stone will better withstand exposure to elements and daily activities.
Recommended stones include:
- Diamond (10): Diamonds are classically elegant, always sought-after, exuding enviable luxury with their famous scintillation. Diamonds come in a wide range of price points, qualities, sizes, cuts, and settings, making them perfect for any fine metal mounting with or without side stones.
- Moissanite (9.25) An eco-friendly alternative to natural stones that is high-quality, long-lasting, glamorous, and beautiful. Show-stopping rainbow brilliance that commands attention makes moissanite unique and captivating. Also durable enough for an engagement ring.
- Sapphire and Ruby (9): Sapphire and ruby are from the same mineral family, corundum. Sapphire is available in a variety of cuts, colors, sizes, and carat weights, making style options readily available. Nothing compares to the rich, luscious red of ruby, one of the world’s most sought-after precious gemstones.
- Topaz (8): Topaz is available in icy light blue, Swiss, or London Blue. Topaz is also available in other colors (i.e. rare Imperial; golden that is common yet beautiful), or even colorless, pink, etc.
6.01 carat Oval Diamond Cathedral Ring
Oval Moissanite Pave Invisible Gallery™ Ring
7.75 Carat Oval Sapphire And Diamond Three-Stone Ring
Maintaining Your Jewelry
Diamonds must be treated with care. Although they rank 10 on the Mohs scale of hardness they are not indestructible. Diamonds can still chip, break, or crack if they are subjected to harsh treatment.
Tips for Taking Care of Your Diamond Jewelry and Engagement Rings
1. Remove your jewelry before any strenuous activity, household chores, heavy lifting, laborious work, moving furniture, etc.
2. Chlorine and salt water can damage your jewelry, especially detailed metalwork, like rustic and fancy finishes. Removing jewelry before swimming will protect it from harsh environmental elements, chemicals, and the risk of being lost.
3. Store all jewelry in jewelry boxes, bags, or pouches when not worn to keep it safe from dust, household cleaning chemicals, or misplacement. Placing jewelry in separate compartments prevents pieces from scratching each other.
4. Clean your jewelry regularly. Here are some recommendations:
- A jewelry cleaning cloth is safe for most jewelry.
- Ultrasonic machines and liquid jewelry cleaners are only suitable for certain stones and metals. Consult a professional before using these methods.
- Warm water with gentle soap and scrubbing with a soft toothbrush are recommended:
- Leave to soak in the soapy water bowl for 5-10 minutes to break up debris.
- Run cool water over the piece to remove the soap.
- Gently pat dry with a soft cloth.
Lauren B Has it All
Lauren B is known for custom engagement rings, wedding bands, and other one-of-a-kind jewelry designs. We can source any gemstone, aiding in the creation process for your jewelry piece. Follow us on Instagram or Pinterest for more inspiration. Have a question? Contact us today with your jewelry design inspirations.
