Mineral

Almandine

Fe₃Al₂(SiO₄)₃Almandin

The commonest garnet: a deep red, iron-rich stone named after the ancient city of Alabanda in Anatolia, used in jewellery and in sandpaper alike.

Also known as: Almandite (chiefly British usage) · Carbuncle (old name for cabochon-cut almandine) · Oriental garnet · Syriam garnet (violet-tinted almandine) · Ceylon ruby and Australian ruby (misleading trade names)

Popularly: Semi-precious stone
Gemstone
Industrial

Photo: Didier Descouens · CC BY-SA 4.0 · Wikimedia Commons

In short

Almandine is the iron-bearing member of the garnet family. Its colour runs from deep red to brownish or purplish red. The most abundant of the garnets, it is common in metamorphic rocks such as mica schist and gneiss. Because it is hard, it is both an affordable gem and, ground up, an abrasive.

Photos

Almandine specimen (2) — Photo: James St. John · CC BY 2.0 · Wikimedia Commons

How does it form?

Almandine is the commonest of the garnets and is found mostly in metamorphic rocks such as mica schist and gneiss. These rocks form when clay-rich sediments are transformed by heat and pressure (metamorphism), and they usually also contain minerals such as biotite, cordierite, staurolite, andalusite and kyanite. Almandine also occurs in granite and eclogite. Because it is hard and durable, it collects in river deposits when the host rock wears away.

Almandine almost always forms mixtures (solid solutions) with other garnets: magnesium-rich mixtures grade towards pyrope, manganese-rich ones towards spessartine. For the family as a whole, see the garnet page.

What is it used for?

Jewellery: Deep red almandine is the commonest garnet gem. Being hard (7–7.5) and without cleavage, it wears well in everyday jewellery. Large stones look very dark, so they are usually cut small to medium. A Roman-period almandine carved with Eros is in the Metropolitan Museum in New York.
Abrasives: Being hard and tough, coarse almandine is crushed and used for abrasive blasting, waterjet cutting and sandpaper. According to the USGS, one of the largest garnet resources in the USA is the coarse-grained gneiss near North Creek, New York.
Science: Garnets record the pressure and temperature at which they grew, so geologists use almandine-bearing rocks to work out the metamorphic history of a region.

Where does the name come from?

Pliny the Elder used the word alabandicus for a stone found or worked at Alabanda in Caria; the name almandine is a corruption of it. The Handbook of Mineralogy ties the name to Alabanda as a stone-cutting centre in antiquity. The ruins of Alabanda lie near Çine in Aydın province today.

Almandine cut as a cabochon used to be called “carbuncle”, a name that comes from the Latin for “live coal”.

In Türkiye

Almandine takes its name from Anatolia, but the almandine found in Türkiye is generally not of gem quality. A doctoral thesis completed at Pamukkale University in 2023 found that garnets around Karacasu, Çine (Aydın), Kayaağıl (Uşak) and Ekinözü (Kahramanmaraş) are almandine porphyroblasts in metamorphic rocks, and that the garnets at Hudutköy are almandine in amphibolite; it noted that the garnets at Çine, Kayaağıl and Hudutköy are altered and have no potential as gemstones.

Almandine 1–3.5 centimetres across, in garnet schists of the Menderes Massif and in young stream deposits between the villages of Eğlence and Belkaya in Uşak, was studied in a 2022 master’s thesis. According to the USGS, garnet deposits in Türkiye have been worked for the domestic market, although production figures are not reported.

What determines its value?

Because almandine is relatively plentiful, it counts among the affordable garnets. Colour matters most: vivid, medium-toned reds and purplish reds are sought after, while very dark, almost black stones attract less interest. Clarity and cut also count; since large almandine looks very dark, it is usually cut small to medium and thin. Stones showing a star effect (asterism) are especially prized by collectors and are among the hardest to cut. The value of industrial almandine, by contrast, depends on purity, grain size and the size of the deposit.

This information is educational, not buying, selling or investment advice. Value varies enormously with quality and treatment.

How to recognise it

1
Crystals are usually twelve-faced (dodecahedra) or twenty-four-faced (trapezohedra), looking like small dark red balls set in the rock.
2
The colour is deep red, brownish red or violet-tinged red; large stones are often so dark that they look almost black.
3
It scratches glass (hardness 7–7.5), feels heavy for its size (specific gravity about 3.95–4.30) and has no prominent cleavage.
4
In a gem laboratory a spectroscope shows three strong absorption bands. Almandine almost always occurs mixed with pyrope or spessartine, and only a laboratory can say reliably which species dominates.

Fakes and imitations

What shops usually don’t tell you:

Synthetic almandine grown by the hydrothermal method has reached the market; traces of growth such as “seed plates” are looked for under strong magnification.
Red glass and other red stones may be sold as almandine.
Misleading names: almandine from Sri Lanka was called “Ceylon ruby” and that from Australia “Australian ruby”; these are garnets, not rubies.
In the 1970s some almandine-pyrope garnets were heated to give their surface a grey metallic sheen and sold as “Proteus garnets”; the product is no longer made.

Myths and misconceptions

MythThe stones called “Ceylon ruby” or “Australian ruby” are rubies.
FactThey are almandine garnets: almandine from Sri Lanka and Australia was long mistaken for ruby and sold under these names. Ruby is the mineral corundum and almandine is a garnet; they are different minerals.
MythCarbuncle is a separate, very valuable stone.
FactCarbuncle is not a mineral name but an old term for red stones cut as cabochons (smooth, domed, flat-backed); today it mostly means cabochon-cut almandine. In the past ruby, spinel and other red stones were also called by this name.

What is it believed to be good for?

This section reports beliefs; it is not health information. There is no scientific evidence for these claims and no stone replaces medical treatment.

Conflict with science:High: contradicts science or may cause harm

The meanings people give this stone, and who holds them:

Kunz, citing the 16th-century scholar Girolamo Cardano, reports that the red stone called “carbuncle” (today mostly cabochon-cut almandine) was believed to stimulate the heart, and that it was thought to make its wearer angry and passionate, so that warnings were given against attacks of apoplexy (stroke).
Today crystal-therapy websites claim that almandine opens the root chakra and gives courage, confidence and stamina.
The same circles say that almandine supports blood circulation and endurance.

What science says

In old records the name “carbuncle” was used for all bright red stones, including ruby, spinel and garnet, so not every such account describes almandine. There is no scientific evidence that almandine stimulates the heart, improves circulation or stamina, or opens a chakra; someone with a heart or circulation problem should not leave treatment to a stone but see a doctor.

Did you know?

A necklace dated to about 3500 BC found in Egypt includes fragments of almandine; almandine has been a jewellery material for thousands of years.

The Barton mine on Gore Mountain in New York produces the largest single garnet crystals in the world, 5–35 centimetres across.

In the 19th century, almandine from the Zillertal in Tyrol was also sold in the trade as “Bohemian garnet” once it was cut; the name did not belong to Czech pyrope alone.

Almandine is the official state gemstone of Connecticut in the USA, while Idaho’s state gem is the rare “star” form of this species.

Where is it found?

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Barton mine, Gore Mountain, North Creek, New York, USA · Major depositGneiss yielding the largest single garnet crystals in the world; a large commercial almandine deposit
Zillertal, Tyrol, Austria · Known localitySharp dodecahedral almandine crystals in schistose rocks; mined in the 19th century, the cut stones were sold in the trade as “Bohemian garnets”
Falun, Dalarna, Sweden · Known localityA classic locality for fine crystals
Wrangell area, Alaska, USA · Known localityWell-formed almandine crystals embedded in mica schist
Trincomalee, Sri Lanka · Known localitySource of fine-coloured, large almandine; almandine is plentiful in Sri Lanka's gem gravels
Jaipur, Rajasthan, India · Known localityAlmandine worked in mica schist; India is also a main source of star garnet
Harts Range, Northern Territory, Australia · Known localityA range in central Australia cited in the mineralogical literature as an almandine locality
Çine (around the ancient city of Alabanda), Aydın, Türkiye · Historic sourceAlmandine is named after Alabanda, a stone-cutting centre in antiquity; metamorphic rocks around Çine hold almandine porphyroblasts, but they are altered and not of gem quality
Uşak (around Kayaağıl and the villages of Eğlence and Belkaya), Türkiye · Known localityAlmandine 1–3.5 cm across in garnet schists of the Menderes Massif and in young stream deposits; documented in academic studies
Ekinözü, Kahramanmaraş, Türkiye · Known localityAlmandine porphyroblasts in metamorphic rocks; documented in academic studies

Locations are approximate to protect sites. Red dots mark places in Türkiye. Open in the big map →

Frequently asked questions

What is almandine?

What is almandine used for?

Jewellery: Deep red almandine is the commonest garnet gem. Being hard (7–7.5) and without cleavage, it wears well in everyday jewellery. Large stones look very dark, so they are usually cut small to medium. A Roman-period almandine carved with Eros is in the Metropolitan Museum in New York. Abrasives: Being hard and tough, coarse almandine is crushed and used for abrasive blasting, waterjet cutting and sandpaper. According to the USGS, one of the largest garnet resources in the USA is the coarse-grained gneiss near North Creek, New York.

How hard is almandine?

It has a hardness of 7–7.5 on the Mohs scale. It scratches glass and steel; a steel knife cannot scratch it. Its specific gravity is 3.95–4.3 g/cm³.

Where is almandine found?

Its best-known localities: Barton mine, Gore Mountain, North Creek, New York, USA; Çine (around the ancient city of Alabanda), Aydın, Türkiye; Zillertal, Tyrol, Austria; Falun, Dalarna, Sweden; Wrangell area, Alaska, USA.

Where is almandine found in Türkiye?

Known localities in Türkiye: Çine (around the ancient city of Alabanda), Aydın, Türkiye; Uşak (around Kayaağıl and the villages of Eğlence and Belkaya), Türkiye; Ekinözü, Kahramanmaraş, Türkiye.

How can you tell if almandine is real?

Crystals are usually twelve-faced (dodecahedra) or twenty-four-faced (trapezohedra), looking like small dark red balls set in the rock. The colour is deep red, brownish red or violet-tinged red; large stones are often so dark that they look almost black. It scratches glass (hardness 7–7.5), feels heavy for its size (specific gravity about 3.95–4.30) and has no prominent cleavage. Synthetic almandine grown by the hydrothermal method has reached the market; traces of growth such as “seed plates” are looked for under strong magnification.

Is almandine valuable?

On the “street to diamond” value ladder it sits on step 5 of nine: Ornamental stone. Because almandine is relatively plentiful, it counts among the affordable garnets. Colour matters most: vivid, medium-toned reds and purplish reds are sought after, while very dark, almost black stones attract less interest. Clarity and cut also count; since large almandine looks very dark, it is usually cut small to medium and thin. Stones showing a star effect (asterism) are especially prized by collectors and are among the hardest to cut. The value of industrial almandine, by contrast, depends on purity, grain size and the size of the deposit.

What is almandine good for?

Kunz, citing the 16th-century scholar Girolamo Cardano, reports that the red stone called “carbuncle” (today mostly cabochon-cut almandine) was believed to stimulate the heart, and that it was thought to make its wearer angry and passionate, so that warnings were given against attacks of apoplexy (stroke). Today crystal-therapy websites claim that almandine opens the root chakra and gives courage, confidence and stamina. The same circles say that almandine supports blood circulation and endurance. In old records the name “carbuncle” was used for all bright red stones, including ruby, spinel and garnet, so not every such account describes almandine. There is no scientific evidence that almandine stimulates the heart, improves circulation or stamina, or opens a chakra; someone with a heart or circulation problem should not leave treatment to a stone but see a doctor. This section reports beliefs; it is not health information. There is no scientific evidence for these claims and no stone replaces medical treatment.