Siderite (pronounced SYE-der-ite) is a tan gemstone popular with collectors for its interesting crystal shape and rare faceted options.
Though faceted options are popular display pieces, the low hardness and perfect siderite cleavage makes cutting it tricky, so jewelry is less common. Their sweet honey color brings warmth to any room!
But what is siderite crystal and what makes it valuable? Come along as we cover everything you need to know about siderite gemstone healing traits, history, properties, prices, and more!
What is the other name for siderite? This stone may also go by “chalybite,” especially siderite from Cornwall, England. Plus, “siderite” is a type of iron meteorite unrelated to this mineral.
The industrial siderite uses are more widespread than its gemstone uses. So, what is siderite used for?
The primary use for siderite is as a source of iron, though it’s only around 50 percent iron. Luckily, it doesn’t contain phosphorus or sulfur, which makes sourcing iron easier.
Additionally, siderite minerals may also be used for creating brown paint pigment and for creating steel (an iron and carbon alloy). Scientists have manufactured synthetic siderite for removing arsenic and fluoride from water, studying agriculture management, and creating lithium ion batteries.
Siderite is an iron carbonate in the calcite group of similar carbonate minerals. The siderite formula is FeCO3. It forms a series with rhodochrosite, with siderite on the iron-dominant end and rhodochrosite on the manganese-dominant end.
Zinc-dominant smithsonite and magnesium-dominant magnesite are also in individual series with siderite. That said, siderite often has impurities of manganese, iron, and magnesium.
The unique crystal shape that collectors seek out in siderite is its rhombohedral form with curved faces. The mineral can also occur as granular, oolitic, or globular masses. Well-formed siderite crystals are rare.
One aspect that’s helpful in identifying siderite is its magnetism. For one, it’s paramagnetic, so it becomes magnetic when heated. Secondly, siderite is antiferromagnetic, meaning atoms next to each other point opposite ways at low temperatures.
Additionally, siderite has a strong birefringence of 0.24 but lacks pleochroism.
The remaining siderite mineral properties are:
Mohs hardness: 3.5-4.5
Color: Shades of brown, reddish-brown, yellow, black, greenish-brown
Crystal structure: Hexagonal (Trigonal)
Luster: Vitreous, silky, pearly, or dull
Transparency: Transparent to opaque
Refractive index: 1.63-1.87
Cleavage: Perfect, rhombohedral, 1-direction on 
Fracture: Conchoidal to uneven
Some types of siderite are only unique in their crystal habit while others are unique in their impurities. Below, we’ll break down each siderite variety.
Pelosiderite (Clay Ironstone): Any sedimentary or concretion siderite type, usually with clay minerals mixed in.
Oligonite (Oligon Spar): Manganese-rich variety, though still iron-dominant
Magniosiderite (Sideroplesite): Magnesium-rich variety, though still iron-dominant
Sphaerosiderite: Variety with radiating crystals forming spherical masses inside
Wood Iron: Fibrous variety
It’s important to note that “wood iron” is also the name of a fibrous goethite variety.
The siderite crystal symbolizes positivity, ingenuity, and passion. It’s largely associated with relaxation, and spiritual practitioners often recommend meditating with siderite to aid in falling asleep more easily.
The name “siderite” derives from the Greek sideros, meaning “iron,” after the stone’s composition. Austrian mineralogist Wilhelm Karl von Haidinger named siderite in 1845.
Similarly, the other name for siderite “chalybite” comes from the Greek term khálups, meaning “steel,” after its composition of carbon and iron.
Though Haidinger was the first to describe siderite in 1845, the mineral has been used and known throughout the world since ancient times.
In that vein, siderite is one of the minerals collected by researchers at the Switzerland research university ETH Zurich to determine what Earth’s climate was like during the Paleocene and Eocene eras.
Siderite’s use as an iron ore started around the 1800s, particularly following the techniques and machines created by Sir Thomas Buckler Lethbridge and steelmaker Charles Sanderson in 1838.
Switching gears, what is siderite crystal as a healing stone?
What about siderite’s uses for emotional, physical, and chakra healing?
Purported physical benefits of siderite include helping with:
Weak, broken, or atrophied bones
Emotionally, siderite is purported to bring positivity, facilitate creative problem-solving, and encourage enthusiasm. Crystal healers highly recommend this crystal in the workspace or during job searches.
Chakra healing is an ancient practice of bringing energy points (chakras) back into balance when they’re blocked, as the blockage causes negative symptoms. Siderite is a chakra stone for balancing the root chakra and solar plexus chakra.
The root chakra governs fundamental needs of stability and connection. When it’s blocked, you may feel insecure and detached.
The solar plexus chakra governs your self-esteem and confidence, so blockages result in feelings of self-doubt.
Siderite opens both chakras, bringing in feelings of boosted confidence, connection with others, and security.
Siderite’s value as a gemstone is determined by where each individual stone falls on the categories of color, cut, clarity, and carat weight.
Siderite’s color goes from yellow to black, though it’s usually in between in pale shades of brown. The brownish hues likely come from its iron content. Black hues are caused by manganese impurities, and these varieties are called manganosiderite.
Besides its low ranking on the Mohs mineral hardness scale, siderite’s perfect cleavage also makes it difficult to facet. Plus, gem-quality crystals are rare, making faceted pieces even harder to come by.
That said, any faceted siderite gems can show attractive colors and some sparkle. Material that forms as masses may become cabochons.
Clarity represents the amount of visible inclusions in a gemstone. Some common inclusions in siderite are jamesonite and fluid inclusions. More often, siderite is an inclusion in other stones like quartz.
Visible inclusions only lower the value of transparent siderite. Inclusions and facet edges may appear doubled in faceted stones because of siderite’s strong birefringence.
Though rough siderite may be large, faceted specimens are almost always 1-5 carats. Any faceted stone above 1-2 carats is significantly more valuable.
Siderite forms in oxygen-deficient environments when ferrous iron reacts with carbonate ions. The mineral is a sedimentary precipitate, meaning it forms when the minerals in water precipitate.
This mineral can also form inside metamorphic rocks. Most often, you’ll find siderite in sedimentary deposits, hydrothermal veins, and banded iron beds.
Where is siderite found? Some of the best siderite comes from Portugal and Brazil.
Additional sources for gem-quality siderite are:
USA (Arizona, Colorado, Connecticut, Idaho, North Carolina)
Now, how much does siderite cost?
The most expensive siderites are faceted gems, as these are rare. Average prices for faceted siderite are $40-$55 per carat. A less expensive faceted option is quartz containing siderite, which fetches $15-$20 per carat.
Rough siderite specimens at wholesale are always under $1 per carat, usually around $0.10-$0.20 per carat.
Lastly, let’s discuss proper gemstone care.
Siderite jewelry isn’t common because it’s so fragile, but if you do find jewelry options, you must handle them with delicacy to ensure they don’t become scratched or broken. Safer jewelry options are pendants, brooches, and earrings.
You can clean siderite with the standard soft toothbrush dipped into a mixture of warm water and mild soap. Rinse the stone well, then dry it with a dust-free microfiber cloth. Avoid using steam or ultrasonic cleaners.
Store your siderite stone away from other gems to avoid scratches.
Though its value is mostly in its industrial uses, siderite gemstones are a rare and beautiful addition to any mineral or gem collection. Their earthy hues are perfect for creating a deeper connection to nature and filling your space with grounding energies!
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