Hematite Stone Properties: Hardness, Density and Streak

Hematite is iron(III) oxide, Fe2O3: a dense, opaque mineral with a Mohs hardness of 5.5-6.5, a specific gravity around 5.3, a metallic lustre and a diagnostic cherry-red to reddish-brown streak. Those five properties explain almost everything about how it looks, how heavy it feels and how it behaves when it is cut into beads. This guide is the mineralogical reference behind the jewellery.

If you want the short cultural version, our what is hematite article covers the story; this one is about the measurable data. Every number below is a standard, verifiable material property rather than a belief or a marketing phrase, and we flag where a value is a range rather than a fixed constant.

Hematite at a glance

Chemical composition: Fe2O3

The formula Fe2O3 means two iron atoms to three oxygen atoms, with iron in its +3 oxidation state. In pure crystalline hematite, iron makes up close to 70 percent of the mass by weight, which is the direct reason the stone is both heavy and an important iron ore. It is the same compound that gives red ochre its colour and that forms when iron oxidises fully.

That composition also explains the name. The Greek haima means blood, and the red of powdered hematite has been used as a pigment since prehistory. It is worth stating plainly: "blood" here is a description of colour, not a claim about the body. HEMIOS sells the bracelet as a wellness accessory and piece of jewellery, not a medical device, and makes no health claims about it. The chemistry is interesting enough on its own.

Crystal system and habit

Hematite crystallises in the trigonal system, commonly forming tabular, plate-like or rhombohedral crystals, and sometimes the glittering, micaceous aggregates called specularite. It also occurs in massive, botryoidal ("kidney ore"), fibrous, earthy and oolitic forms. Because there is no true cleavage, it does not split along clean flat planes the way mica or calcite does; it tends to break unevenly instead.

For bead cutting, the massive and finely granular varieties matter most. A cuttable, dense mass can be tumbled into consistent spheres and polished to a mirror finish, while a crumbly earthy form cannot. That is a practical selection criterion at the source, long before a strand reaches a jewellery bench.

Hardness: Mohs 5.5-6.5

The Mohs scale is a scratch-hardness comparison, not a measure of toughness. Hematite's 5.5-6.5 places it above window glass and a steel knife blade, but below quartz (7), topaz (8) and corundum (9). In everyday terms, a hematite bead will not be scratched by dust or a fingernail, but it can be scratched by quartz sand, a harder gemstone or an abrasive polishing cloth, and it can chip on a sharp blow against a hard surface.

Hardness and brittleness are different things, and hematite is somewhat brittle despite being reasonably hard. A drop onto a tiled floor is more likely to chip an edge than to scratch the surface. That is why the care routine is built around soft cloths, a separate pouch and avoiding knocks, not around heavy-duty cleaning. Hard enough for daily wear is not the same as indestructible.

Density and specific gravity ~5.3

Specific gravity compares a material's density with water. At roughly 5.3, hematite is more than five times as dense as water and about twice as dense as quartz (2.65) or common glass (around 2.5). This is the single property people notice first when they pick up a bracelet: a strand of 8 mm beads feels unexpectedly, almost surprisingly, heavy for its size.

The heft is also a useful, non-destructive authenticity check. Compare a suspected bead with a same-size glass bead and the difference is obvious in the hand. A manufactured ferrite bead can be engineered to a similar density, so weight confirms heaviness rather than geological origin, but a very light "hematite" bead is an immediate warning sign. Our authenticity page sets out the full checklist.

Streak: the diagnostic red-brown

Streak is the colour of a mineral's fine powder, produced by rubbing it across an unglazed porcelain plate. Hematite's streak is cherry-red to reddish-brown and, crucially, it is consistent even when the specimen itself is steel-grey or black. Most dark lookalikes — obsidian, black glass, dyed agate, black tourmaline — leave a white or colourless streak, so this one test separates hematite from a long list of imitations.

The reason is that streak reveals powdered material rather than a polished surface, and hematite's powder is red iron oxide. It is a genuinely diagnostic property, which is why mineralogists reach for a streak plate before almost anything else. For a finished bracelet, test a spare bead or an inconspicuous edge; see Understanding Hematite for the practical version.

Lustre, colour and named varieties

Polished hematite has a metallic to submetallic lustre — a cool, mirror-like sheen — while earthy forms look dull and red-brown. Colour ranges from steel-grey to near-black in massive pieces, with occasional iridescent tarnish. It is opaque at any thickness, so there is no clarity or refraction grading as there would be for a transparent gemstone.

• Specularite / specular hematite: sparkling, plate-like aggregates with a micaceous glint.
• Kidney ore: rounded, botryoidal masses with a smooth reniform surface.
• Red ochre: soft, earthy hematite used as a pigment since prehistory.
• Tiger iron: a banded rock combining hematite, jasper and quartz.
• Martite: hematite that has replaced magnetite while keeping its crystal shape.

Where hematite is found

Hematite is one of the most widespread iron minerals and forms in sedimentary, metamorphic and igneous environments, often through the oxidation of other iron-bearing minerals or as a precipitate in ancient banded iron formations. Major commercial sources include Brazil, Australia, India, the United States, South Africa and China, and it is mined at enormous scale as the world's principal iron ore.

For jewellery, what matters is not the tonnage but whether a deposit yields dense, uniform, polish-able material in bead sizes. That is a much narrower supply chain than bulk ore, and it is why a good strand is a selected product rather than a generic commodity. We describe what we verify in Understanding Hematite.

What the properties mean for a bracelet

Put the numbers together and the behaviour of the finished piece follows: the density gives it weight, the hardness lets it survive daily wear but not hard knocks, the metallic lustre gives the understated look, the lack of cleavage means uneven rather than clean breaks, and the red streak gives you a way to verify it. Those are verifiable facts about a material.

Traditional crystal lore adds symbolic meanings such as grounding, which are personal beliefs rather than measurable properties, and claims of health outcomes are not supported by reliable scientific evidence. HEMIOS makes no such claims. We sell the HEMIOS Hematite Bracelet as a wellness accessory and piece of jewellery, not a medical device — chosen for how it looks and feels.

Frequently asked questions

What is hematite made of?

Iron(III) oxide, Fe2O3, an oxide mineral containing roughly 70 percent iron by weight in its pure form.

How hard is hematite?

5.5-6.5 on the Mohs scale: harder than glass, softer than quartz, and somewhat brittle under a sharp impact.

Why is hematite so heavy?

Its specific gravity is about 5.3, more than twice that of quartz or common glass, due to its high iron content.

Why does a black stone leave a red streak?

Because streak shows the colour of the powdered mineral, and hematite powder is red iron oxide regardless of the polished surface colour.

Is hematite a crystal or a rock?

It is a mineral that forms trigonal crystals, but it also occurs in massive and earthy aggregates used as an ore and pigment.

Editorial note: This article is for general information only and describes mineralogical properties. HEMIOS sells the Hematite Bracelet as a wellness accessory and piece of jewellery, not a medical device, and makes no health claims. See our Transparency & Safety page and our Understanding Hematite guide for full detail.