The Mohs Hardness Scale Peridot Rating: 6.5 to 7 Explained

The Mohs hardness scale peridot rating is 6.5 to 7, a number that tells you a good deal about how this olive-green gem behaves in a ring, a pendant or a collector’s tray. It means peridot shrugs off most everyday scratches, yet it sits right at the hardness of quartz, the mineral found in ordinary dust and grit. That small gap explains why a peridot can stay bright for years in a pair of earrings and slowly lose its crisp facet edges on a hand that does a lot of work.

Below you’ll find what the scale actually measures, why the Mohs hardness scale peridot range lands where it does, how it compares with other gems, what that means for jewelry, and how people clean and store it. Along the way there is a little folklore too, because few gems have a stranger origin story than this one.

The Mohs Hardness Scale Peridot Rating Explained

Mohs hardness is a measure of how well a mineral resists being scratched, ranked from 1 (softest) to 10 (hardest). A mineral can scratch anything below it on the scale and can be scratched by anything above it. Peridot is given a range of 6.5 to 7 rather than one neat number because it is a natural mineral whose chemistry varies a little from stone to stone, as you’ll see in the geology section.

Read the Mohs hardness scale peridot figure as a set of comparisons rather than an abstract score:

• Peridot is harder than window glass, which sits around 5.5 (see our guide to glass on the Mohs scale), and most ordinary steel, so a key or kitchen knife will not usually mark it. Our article on steel hardness ratings covers how blades vary.
• Peridot is roughly equal to quartz at 7. Quartz grains are common in dust, sand and many stone countertops, and that is the everyday abrasive that wears gems down over time.
• Peridot is softer than topaz, sapphire, ruby and diamond, all of which can scratch it if they rub together in a jewelry box.

One more thing worth knowing: the scale is ordinal, meaning it only ranks minerals in order. The steps are not equal in size. The jump from 9 (corundum) to 10 (diamond) is far bigger than the step from 6.5 to 7, so peridot and quartz are true neighbours, while diamond is in a league of its own.

How the Mohs Scale of Mineral Hardness Works

The scale was devised by the German mineralogist Friedrich Mohs in the early nineteenth century as a quick field method. Instead of measuring force, he chose ten common minerals as fixed reference points and ranked everything else by what it could scratch:

1. Talc
2. Gypsum
3. Calcite
4. Fluorite
5. Apatite
6. Orthoclase feldspar
7. Quartz
8. Topaz
9. Corundum
10. Diamond

Peridot slots in between orthoclase and quartz. If you want to meet each of the reference stones in turn, our piece on the ten minerals on the Mohs hardness scale walks through them one by one.

Hardness is not the same as toughness

This is the single most useful idea for anyone who wears peridot. Hardness is resistance to scratching. Toughness is resistance to chipping and breaking when a stone is knocked or dropped. The two do not always travel together, which is why the Mohs hardness scale peridot score of 6.5 to 7 says nothing on its own about how the stone handles a sharp blow.

Peridot has poor cleavage, meaning it does not split readily along flat planes the way some crystals do. When it breaks, it shows a conchoidal fracture: a curved, shell-like surface, the same kind of break you see on chipped glass. In practice that means peridot’s weak points are its thin facet edges and pointed corners, which can chip if they strike a door frame or tile floor.

A note on scratch testing

A Mohs hardness test kit is a lovely teaching tool for rough specimens, and checking the Mohs hardness scale peridot range on a cheap piece of rough olivine can be satisfying. But scratch testing is destructive. Never test a faceted peridot or a piece of jewelry this way. Gemologists identify cut stones with optical tests instead, and peridot has a distinctive optical clue we’ll come to in the colour section.

What Peridot Is: Olivine From the Earth’s Mantle

Peridot is the gem-quality form of olivine, a silicate mineral made of magnesium, iron, silicon and oxygen. Its chemical formula is written (Mg,Fe)2SiO4, and the comma inside the brackets is the key: magnesium and iron can substitute for one another in the crystal structure. The gem variety sits close to the magnesium-rich end of the olivine family, known as forsterite. It crystallises in the orthorhombic system, and older texts sometimes call it chrysolite.

That swapping of magnesium and iron explains the spread in the Mohs hardness scale peridot range, and it also drives the stone’s colour and density. As iron rises, the specific gravity (how heavy the stone is for its size) climbs, the colour darkens and the refractive index increases.

Born deeper than almost any other gem

Most gems form in the Earth’s crust. Peridot is one of only two gems, along with diamond, known to form in the molten rock of the upper mantle. Olivine is common in dark, silica-poor rocks called mafic and ultramafic rocks. Rising lava can tear off chunks of mantle rock called peridotite xenoliths (a xenolith is a fragment of foreign rock carried inside another) and deliver them to the surface in basalt.

Peridot also turns up somewhere stranger: inside pallasite meteorites, stony-iron meteorites in which olive-green crystals sit in a metal matrix. Peridot from space differs chemically from earthly peridot, most notably in lacking nickel.

Why gem-quality peridot is scarce

Olivine is abundant, but clean, sizeable crystals are not. On its long trip up from the mantle and once exposed at the surface, olivine alters and weathers easily, so it usually survives only as small, cloudy grains. The same chemical sensitivity shows up in the lab: peridot is slowly attacked by hydrochloric acid, breaking down into a gel-like silica. That detail matters for cleaning, as you’ll see below.

Where peridot is found

Peridot was mined in the ancient world on St. John’s Island in the Red Sea from around 300 BCE. Today the principal source is the San Carlos Apache Indian Reservation in Arizona, with other deposits in Arkansas, Hawaii, Nevada and Kilbourne Hole in New Mexico, as well as Australia, Brazil, China, Egypt, Kenya, Mexico, Myanmar, Norway, Pakistan, Saudi Arabia, South Africa, Sri Lanka and Tanzania.

Inclusions often hint at origin. San Carlos stones can show “lily pad” inclusions, flat circular discs around a tiny cavity. Hawaiian peridot commonly holds rounded gas bubbles, and Pakistani material often shows silky, rod-like inclusions. The largest known cut peridot weighs about 310 carats and is held in the Smithsonian’s gem collection in Washington, D.C.

You’ll find peridot’s neighbours in the Earth treasures section of the crystal library.

How Peridot Compares With Other Gemstones

Set the Mohs hardness scale peridot rating beside other popular stones and its place in the jewelry world becomes clear. Our broader gems hardness chart and the guide to gemstone hardness and toughness go further, but here is the short version:

The table shows why the Mohs hardness scale peridot position matters most in two situations: everyday abrasion from quartz-rich grit, and contact with harder gems. A peridot pendant tossed into a drawer with a sapphire ring and a topaz bracelet will come off worst every time.

Is Peridot Hard Enough for a Ring?

Yes, with some thought. The Mohs hardness scale peridot figure is the first thing jewelers weigh when suggesting a setting, and 6.5 to 7 sits at the lower edge of what most people consider comfortable for an everyday ring. Earrings and pendants, which rarely bump into anything, are where peridot truly shines.

A worked example

Picture two identical oval peridots cut from the same rough. One goes into a pendant, the other into a ring with tall four-prong claws that the owner wears daily, including while cooking, gardening and wiping down a granite counter.

Both stones carry the same Mohs hardness scale peridot rating, yet they age very differently. The pendant hangs against fabric and skin, touches little that is harder than itself, and keeps sharp facets for years. The ring meets quartz grains in soil, sand in a garden glove and the stone surface of the counter (granite contains quartz, as our granite hardness article explains). Over time the facet junctions on its table soften into a slightly hazy look, and a corner caught on a cupboard edge could leave a small shell-shaped chip.

Now change one variable: the same ring in a bezel setting, where a rim of metal wraps the stone’s edge. The top still meets grit, but the vulnerable girdle and corners are shielded. Remove the ring before gardening and cleaning and it can look bright for a very long time. That’s the trade-off in a sentence: peridot rewards protective settings and sensible habits.

Practical ring choices

• Settings: bezel, half-bezel or halo designs protect edges better than tall open prongs.
• Shapes: rounded shapes such as ovals and rounds have fewer sharp points than marquise, pear or princess cuts.
• Cabochons: a smooth, domed cabochon (an unfaceted polished stone) has no crisp edges to chip and hides light abrasion well, which makes it a forgiving match for the Mohs hardness scale peridot range.
• Wear pattern: treat a peridot ring as an occasional or careful-wear piece, and take it off for sport, chores and the gym.

Peridot Colours, Meanings and Traditions

Peridot is one of very few gems that comes in essentially one colour: green with an olive or yellow cast. The shade is set by iron. Stones with less iron are lighter and more yellow-green, while stones with more iron move toward deep olive and brownish green. Rarely, a stone shows a pure, medium-dark green with no yellow or brown undertone. Every shade falls within the same Mohs hardness scale peridot rating of 6.5 to 7, so colour is not a clue to durability.

The lustre is glassy to slightly oily, and peridot shows weak pleochroism, meaning its tint shifts subtly when viewed from different directions. Its most useful identifying feature is strong double refraction: under a loupe, the back facet edges of a cut peridot appear doubled, like a faint echo of each line. Glass imitations do not show this.

Meanings in crystal traditions

In crystal traditions, peridot is associated with the heart chakra. A chakra, in yogic and modern energy-work traditions, is one of the body’s believed energy centres, and the heart chakra is linked with compassion, openness and emotional balance. Many people use peridot as a stone of renewal and warmth, and it is believed to help release resentment and jealousy. Its sunny green has long tied it to ideas of growth, good fortune and abundance, and older folklore treated it as a protective stone, worn to ward off bad dreams and ill will. Our list of crystals people use for protection places it among other stones with that reputation.

Peridot is a modern birthstone for August, sharing the month with spinel and the traditional sardonyx; see the full birthstones chart by month. In some Vedic astrology practice it is treated as an alternative to emerald, the gem linked with Mercury.

These are beliefs and customs, not proven effects, and that is how this journal approaches them (you can read more on our editorial approach). People who work with peridot commonly:

• carry a tumbled stone (one smoothed and polished in a rotating barrel) in a pocket as a reminder of an intention, ideally in a small pouch, since the Mohs hardness scale peridot rating means keys and coins with grit on them can dull it;
• hold a raw piece (natural, unpolished rough) or a small peridot-in-basalt specimen during a quiet meditation focused on the heart;
• wear it as earrings or a pendant close to the chest;
• place a small dish of loose stones on a desk or windowsill where the green catches the light.

If you’re building a small set of stones across the hardness scale to see these differences in your own hands, Spirit Magicka, the journal’s own crystal shop, is one place to begin.

How to Clean and Store Peridot

Cleaning is where the Mohs hardness scale peridot rating turns into daily habits. The goal is to remove skin oils and grime without grit, heat shock or acid.

1. Prepare a bowl of lukewarm water with a drop of mild, unscented dish soap.
2. Soak briefly, a few minutes is enough to loosen film behind the stone.
3. Brush gently with a very soft toothbrush, paying attention to the underside of the setting where dirt collects.
4. Rinse in clean lukewarm water of the same temperature, avoiding a jump from warm to cold.
5. Dry with a soft, lint-free cloth and let the setting air-dry fully before storing.

Peridot is not water-soluble, so a brief rinse is safe for loose stones and jewelry alike. For those who like an energetic cleansing ritual, moonlight, sound from a bell or singing bowl, or resting the stone on a clean cloth are all gentle options that put no stress on the gem.

Storage

Keep peridot in its own soft pouch or a lined compartment, away from diamonds, sapphires, rubies, topaz and quartz pieces. Because of the Mohs hardness scale peridot position just below those stones, separate storage is the simplest way to keep facets crisp. Avoid storing it where it can rattle against hard surfaces in a bag or drawer.

Common mistakes to avoid

• Assuming hardness means toughness. The Mohs hardness scale peridot score of 6.5 to 7 resists scratches, not knocks. Sharp blows chip edges.
• Using acidic cleaners. Peridot is slowly attacked by acid, so skip vinegar, lemon juice and harsh jewelry dips.
• Steam cleaners and sudden heat. Peridot should be kept away from thermal shock, so avoid steamers, hot-to-cold rinses and leaving it near a heat source.
• Ultrasonic cleaners. Vibration can worsen existing inclusions or fractures; hand cleaning is safer.
• Wiping with a dry, dusty cloth. Dust carries quartz-hard particles that can haze the surface. Clean wet, then dry.
• Scratch-testing a cut stone to check if it is real. It damages the gem; look for doubled facet edges with a loupe or ask a gemologist.
• Making crystal elixirs carelessly. Even with a stone that tolerates water, many settings and mixed-stone pieces do not; if you want to try this ritual, use the indirect method with the stone outside the drinking vessel, and keep loose stones well away from children and pets, who may swallow them.

Keep the Mohs hardness scale peridot rating in mind and the rest follows naturally: let it hang, sparkle and rest in protected settings, keep it away from grit and harder gems, and clean it gently. A stone that travelled up from the Earth’s mantle, or arrived in a meteorite, deserves that little bit of care. When you’re ready to explore beyond peridot, the full crystal library is a good next stop, and Spirit Magicka is the journal’s own shop for crystals and minerals.