You've found the perfect piece of jewelry, but how will it hold up to daily wear? Will your new ring scratch easily? Is one gemstone more durable than another?
Understanding a gemstone’s durability is key to protecting your investment and ensuring your treasured pieces last a lifetime. The first step to a smart purchase is knowing its hardness, and for that, we turn to a simple yet powerful tool: the Mohs Scale.
What is the Mohs Scale?
The Mohs Scale is a ranking from 1 to 10 that measures a mineral’s resistance to being scratched. Devised by German mineralogist Friedrich Mohs in 1812, the scale is based on a simple scratch test: a harder mineral will leave a visible mark on a softer one.
The numbers represent ten different minerals, starting with the softest (talc) and ending with the hardest (diamond). It's crucial to understand that this is a relative scale, not a linear one. The difference in hardness from Talc (1) to Gypsum (2) is small. However, the jump from Corundum (9) to Diamond (10) is enormous. In fact, that's why a diamond engagement ring can withstand years of daily wear, while softer stones, like opal, need special care.
Understanding the Mohs Scale:
This table provides a quick reference for the hardness of many popular gemstones, helping you understand how they will stand up to everyday wear.
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To get a hands-on feel for the scale, here are a few common objects you can use as reference points:
- Your Fingernail: Approximately Mohs 2.5
- A Copper Penny: Approximately Mohs 3.5
- A Steel Knife Blade: Approximately Mohs 5.5
Hardness vs. Toughness: A Crucial Distinction
It’s easy to assume that a harder mineral is automatically tougher, but that's not the case. The Mohs Scale measures hardness, a material’s resistance to being scratched. It doesn't measure toughness, a material’s resistance to breaking, chipping, or shattering from impact.
- Diamond: Hard but Brittle While a diamond is a 10 on the Mohs Scale and won't be scratched by any other mineral, it can still chip or break if struck sharply. This is because its perfect internal cleavage makes it prone to splitting along certain planes. Think of a piece of glass: it’s hard to scratch, but a sharp tap can shatter it.
- Jade: Softer but Tough On the other hand, jade (both nephrite and jadeite) ranks at a 6 to 7, making it much softer than a diamond. However, its unique interlocking fibrous crystal structure makes it incredibly tough and resistant to breaking. Jade can handle bumps and drops far better than a diamond without chipping, which is why it has been used for centuries for tools and intricate carvings.
This distinction is vital for a jewelry buyer. While a hard stone like a diamond is perfect for a ring that might encounter abrasive dust, a tough stone like jade is a fantastic choice for a ring that might take a direct hit.
Your Birthstone on the Mohs Scale: What to Know
Birthstones hold personal significance for many, but their beauty also comes with varied durability. Understanding where your birthstone falls on the Mohs Scale is crucial for proper wear and care:
- Extremely Durable (Mohs 9-10):
- April: Diamond (10) – The ultimate in durability for everyday wear.
- July: Ruby (9) – An excellent, durable choice for any piece of jewelry.
- September: Sapphire (9) – Ideal for daily wear, including engagement rings.
- Very Durable (Mohs 7.5-8):
- May: Emerald (7.5-8) – Durable for most jewelry, but be mindful of inclusions that can make it vulnerable to hard impacts.
- March: Aquamarine (7.5-8) – A durable choice, though its crystal structure can require extra care to prevent chipping.
- December (Blue): Topaz (8) – A strong choice for regular wear.
- Durable with Care (Mohs 6.5-7.5):
- February: Amethyst (7) – A robust quartz suitable for daily wear.
- August: Peridot (6.5-7) – Generally durable, but can be sensitive to acids and thermal shock.
- October: Tourmaline (7-7.5) – A versatile gem that is suitable for most jewelry.
- January: Garnet (6.5-7.5) – Ranges in hardness, generally suitable for regular wear.
- November: Citrine (7) – A durable quartz that holds up well.
- Fragile (Mohs 2.5-6.5):
- June: Pearl (2.5-4.5) – Very soft, easily scratched, and vulnerable to acids and chemicals. Ideal for earrings or necklaces, store separately.
- October: Opal (5.5-6.5) – Very delicate, susceptible to scratches, impacts, and dehydration. Best for pendants or special occasion rings.
Why the Mohs Scale Matters for Your Jewelry
Your jewelry is an expression of your life, so choose pieces that can handle it. The Mohs Scale is your guide to making smart choices.
- For Everyday Wear: If you're looking for a ring to wear daily, prioritize gems with a Mohs rating of 7 or higher. Think about the peace of mind you get from a tough and scratch-resistant sapphire or diamond.
- For Special Occasions: Softer stones like pearls or opals are stunning, but their lower hardness means they are best suited for pieces that won't face much wear, such as earrings, pendants, or brooches.
- For Proper Care: A gem's hardness dictates how you clean it. You can safely clean a diamond with a stiff brush and warm, soapy water. However, a softer gem like a pearl, opal, or turquoise should only be wiped with a soft, damp cloth and kept away from harsh chemicals and ultrasonic cleaners.
- For Smart Storage: Always store your jewelry in separate pouches or divided organizers. A hard diamond or sapphire can easily scratch a softer topaz or amethyst, causing irreversible damage.
Frequently Asked Questions (FAQs)
Q: Is sapphire harder than diamond? A: No. Diamond is a 10 on the Mohs Scale, while sapphire is a 9. While sapphire is an extremely hard and durable gemstone, it can be scratched by a diamond.
Q: What is the best gemstone for an engagement ring? A: The best gemstones for engagement rings are those with a high Mohs rating of 9 or 10, such as diamond, sapphire, and ruby. These stones are highly resistant to scratches and can withstand years of daily wear.
Q: Can a diamond break or chip? A: Yes. While diamond is the hardest mineral (most scratch-resistant), it is not the toughest. A diamond can still chip or break if struck with a sharp blow, especially along its natural cleavage planes.
Q: Why does my jewelry get scratched? A: Often, jewelry is scratched by common dust. Many types of dust contain tiny particles of quartz, which is a 7 on the Mohs scale. If your gemstone has a hardness below 7, it is susceptible to scratches from the air around you.
