Mohs Hardness of Gemstones: Which Stones Scratch and Which Don't

The Mohs hardness determines whether a gemstone will remain pristine for years or become covered in scratches within a few months. It's the most important characteristic you don't see when buying a bracelet, and precisely what we pay attention to in the studio before a stone passes selection. In our gemstone bracelet collection, every stone has its own hardness, and knowing it is the difference between a bracelet that stays beautiful and one you replace.

What the Mohs Scale Exactly Measures

The Mohs scale, established by German mineralogist Friedrich Mohs, ranks minerals by their scratch resistance. The principle is simple: a stone with a higher number scratches a stone with a lower number, but not vice versa. Diamond is at the top at 10 and scratches everything, while talc is at the bottom at 1 and can be scratched by almost anything. It's a relative order, not an exact unit of measurement.

This relative nature is important to understand. The difference between Mohs 7 and 8 is actually much greater than between 1 and 2. For bracelets, the practical limit is around quartz, which is at 7. Dust in the air contains many quartz particles, so a stone softer than 7 can eventually get scratches simply by being worn. That sounds more concerning than it is, because with a few habits, even a softer stone will remain beautiful for years.

The Hardness of Our Stones at a Glance

Below are the natural stones we use most often, ranked from hard to soft. The advice column tells you how best to wear and store each stone. Use this table as a reference when assembling a stack, as mixing a hard and a soft stone in the same storage is the most common cause of scratches.

Softer Stones Versus Harder Stones in Practice

Stones above 6.5 on the scale can be treated as you wish. Tiger's eye, agate, jasper, and onyx are quartz-like stones that can withstand a normal life: a day at work, exercising without impacts, and a night on the bedside table without anything happening. These are the stones we recommend if someone is wearing a bracelet for the first time and doesn't want to worry about maintenance.

Stones below 6 require a little more awareness. Obsidian, lapis lazuli, and lava stone scratch more easily and dull faster if treated carelessly. This doesn't mean they are fragile, but it does mean you should store them separately from your harder stones and remove them during rough work. Bead size also plays a role: in 6mm, a softer stone appears more subtle and absorbs fewer impacts than a coarser 8mm bead. Our guide on 6mm or 8mm helps you choose the right proportion.

• Store softer stones separately from tiger's eye, agate, and jasper to prevent mutual scratching
• Remove bracelets with obsidian, lapis lazuli, or lava stone before sports, chores, and the sauna
• Always spray perfume and cologne first, then put on the bracelet
• Clean with a dry, soft microfiber cloth and never with an ultrasonic cleaning bath

How We Check Hardness and Quality in the Studio

The Mohs value from a table is a starting point, not a guarantee. Two pieces of the same stone type can differ in quality due to how compact the material is and how well it's polished. That's why we don't just rely on theory. Every batch of beads is hand-sorted before it ends up in a bracelet, and we pay attention to a few things that no table tells you.

We feel if a stone is evenly polished, because a rough finish often indicates softer or more porous material. We sort by color depth and visible fractures, and when assembling stacks, we consider the mutual hardness so that a softer stone doesn't permanently rub against a harder one. If you want to delve deeper into our selection and buying criteria, read our guide on buying gemstones or the material knowledge behind hematite, one of our most ordered base stones.

Frequently Asked Questions