# Anyolite

- Page: https://taslar.bumba.tr/en/stones/anyolite/
- Turkish: Anyolit
- Also known as: Ruby in zoisite, Ruby zoisite, Tanganyika artstone
- Kind: Rock
- Classification: Rocks › Metamorphic rocks › Non-foliated
- Hardness (Mohs): 6–9
- Specific gravity: 3.5–3.9 g/cm³
- Lustre: Vitreous (glassy), Dull
- Transparency: Opaque
- Colours: bright green, red, pinkish red, violet-red, black-spotted
- Composition: Mainly green, chromium-bearing zoisite, with red to pink ruby (corundum) crystals and black or dark green amphibole (pargasite) grains.
- Texture: Granular and massive; hexagonal ruby crystals (porphyroblasts) several centimetres across, rarely larger, sit in a fine-grained green groundmass. Foliation is weak or absent.
- Value ladder: 5/9 step, Ornamental stone

A Tanzanian rock of green zoisite, black amphibole and red ruby crystals: the colourful ornamental stone known as “ruby in zoisite”.

Anyolite is a metamorphic rock made of bright green zoisite with red to pink ruby crystals and black amphibole spots set in it. It is also sold as “ruby in zoisite”. It was found in 1954 at the Mundarara Mine near Longido in Tanzania. Its rubies are mostly opaque, meaning light does not pass through them, so the stone is not faceted for rings but carved into figurines and bowls or made into beads and cabochons.

## How does it form?

Anyolite occurs in north-eastern Tanzania among rocks that were transformed under high temperature and pressure during the Pan-African mountain building of the Neoproterozoic (roughly 1 billion to 540 million years ago), when old pieces of continent collided to form Gondwana. According to the geologist James St. John, the original rock was an anorthosite containing chromite crystals: during metamorphism the chromite broke down, and the chromium it released turned the zoisite green and the corundum red.

Exactly how the rock formed is still debated. At Mundarara the ruby-bearing zoisite occurs in veins of amphibole, zoisite and plagioclase within amphibolites. The rock grades continuously from amphibole-rich to zoisite-rich parts, so it is not certain whether anyolite is a transformed intrusive rock, a product of fluids from outside changing the rock's chemistry (metasomatism), or a result of partial melting.

## What is it used for?

- **Carvings and ornaments:** The sharp contrast of green, red and black makes it a popular material for figurines, bowls and similar decorative objects.
- **Jewellery:** It is used as cabochons, beads and tumbled (rounded and polished) stones in necklaces, bracelets and earrings.
- **A source of ruby:** The Mundarara Mine occasionally yields ruby clear enough to facet, but most of the material goes to carving.
- **Collecting:** Rough or partly polished pieces find a place in mineral collections.

## Discovery and name

According to GIA, ruby has been known in the Longido area for about a hundred years, making it one of the longest-known ruby occurrences in Africa. The ruby-bearing green rock was found in 1954 at the Mundarara Mine, about 27 km west of Longido, and named anyolite after the Maasai word for “green”. The name has never been accepted as an official rock name; scientific writing uses descriptive names such as “corundum-amphibole zoisitite”.

## The “Gem of Tanzania” affair

In 2009 the accounts of a bankrupt British construction company listed a large 2.1-kilogram “ruby” as its most valuable asset. During the insolvency, examiners found that the stone was not of a quality that could be cut and was in fact a lump of low-value anyolite; the documents that had put a high value on it also turned out to be forged.

## How to recognise it

- It is easy to recognise by its three colours together: a vivid green groundmass, red, pink or violet-red ruby crystals in it, and scattered black spots.
- The ruby crystals are often flattened hexagons and let no light through; only rarely do they have translucent patches.
- The green groundmass is hard (Mohs 6–6.5) and does not flake under a knife. In the look-alike ruby in fuchsite the groundmass is a soft mica (2–3): a knife lifts off flexible flakes that glitter in sunlight.
- In ruby in fuchsite the ruby is often rimmed by pale blue kyanite; this blue mineral does not occur in anyolite.

## What determines its value?

Anyolite is an ornamental stone, and colour contrast matters most: large, deep red, well-shaped ruby crystals in a vivid green groundmass are the most sought after. For carving material, size, freedom from cracks and the quality of the work count. Because most of the rubies are opaque, value does not climb with the amount of ruby as it would for a gem; the rare transparent rubies from the same mine are cut separately and judged on their own.

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

## Myths and misconceptions

- Myth: Anyolite is a variety of the mineral zoisite. Fact: Anyolite is not a single mineral but a rock made of green zoisite, dark amphibole (pargasite) and ruby. It is sometimes wrongly advertised as a variety of zoisite.
- Myth: Because it contains ruby, a big lump of anyolite is worth a fortune. Fact: The rubies in anyolite are mostly opaque and not good enough to be cut as gems. In 2009 the 2.1-kilogram “Gem of Tanzania”, listed as the most valuable asset of a bankrupt British company, turned out on examination to be a lump of low-value anyolite.
- Myth: Ruby in zoisite and ruby in fuchsite are the same stone. Fact: Both have ruby in a green groundmass, but the groundmass differs: in anyolite it is hard zoisite, while in ruby in fuchsite (from places such as India and Zimbabwe) it is fuchsite, a soft, chromium-bearing mica.

## 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.

- Crystal-therapy and bead-seller websites claim that ruby in zoisite gives artists creativity and helps people stay true to their own individuality.
- The same sources say that, because green zoisite and red ruby occur together, the stone is good for the heart and circulation and balances the heart chakra.

What science says: There is no scientific evidence that anyolite boosts creativity or benefits the heart or circulation. The red of ruby comes from chromium atoms, and so does the green of the zoisite; these colours have nothing to do with blood or the heart. Heart and circulation complaints always call for a doctor.

## Curious questions

**Are the red crystals in anyolite real rubies?**

Yes. The red crystals are corundum, the same mineral as ruby. But most are cloudy and opaque; transparent ruby fit for faceting turns up only occasionally at Mundarara. Most of the material goes to carvers.

## Did you know?

- The name comes from anyoli, the Maasai word for “green”. It has also been sold as “Tanganyika artstone”, after the old name of mainland Tanzania.
- The flattened hexagonal ruby crystals at the Mundarara Mine can reach 30 centimetres across.
- The chromium that colours both the zoisite and the ruby comes from chromite crystals in the original rock that were broken down during metamorphism.
- The transparent rubies occasionally found at Mundarara contain far more chromium than other African rubies; this chemical fingerprint can help show where a stone came from.

## Where is it found?

- Mundarara Mine, about 27 km west of Longido, Arusha Region, Tanzania (Type locality): Where anyolite was first found in 1954 and still its main source; ruby crystals here can reach 30 cm

## Sources

- [Anyolite](https://en.wikipedia.org/wiki/Anyolite), Wikipedia
- [Anyolite (Atlas of metamorphic rocks)](https://www.alexstrekeisen.it/english/meta/anyolite.php), alexstrekeisen.it
- [Mundarara Mine, Longido District, Arusha Region, Tanzania](https://www.gemdat.org/loc-8256.html), Gemdat.org (Hudson Institute of Mineralogy)
- [Preliminary observations on facet-grade ruby from Longido, Tanzania (Gem News International), Gems & Gemology 53(4)](https://www.gia.edu/gems-gemology/gems-gemology/winter-2017-gemnews-preliminary-observations-facet-grade-ruby), GIA, 2017
- [Ruby-zoisite (anyolite) and ruby-fuchsite: telling the lookalikes apart](https://epigem.de/en-us/informations/lookalikes/ruby-zoisite-anyolite-fuchsite.html), Epigem
- [Anyolite (corundum-amphibole zoisitite), Mundarara Mine, Tanzania (photo description by James St. John)](https://commons.wikimedia.org/wiki/File:Anyolite_(corundum-amphibole_zoisitite)_(Neoproterozoic;_Mundarara_Mine,_about_27_km_west_of_Longido,_Tanzania)_1_(15098298782).jpg), Wikimedia Commons
- [Tz gem a fake (AFP)](https://capitalfm.africa/tz-gem-a-fake/), Capital FM, 2009


Source: https://taslar.bumba.tr/en/stones/anyolite/ · Licence: CC BY-SA 4.0