# Pyrargyrite

- Page: https://taslar.bumba.tr/en/stones/pyrargyrite/
- Turkish: Pirarjirit
- Also known as: Dark red silver ore, Ruby silver, Ruby blende
- Kind: Mineral
- Classification: Minerals › Sulfides and sulfosalts
- Chemical formula: Ag₃SbS₃
- Crystal system: Trigonal
- Hardness (Mohs): 2.5
- Specific gravity: 5.82–5.86 g/cm³
- Lustre: Adamantine
- Transparency: Translucent
- Colours: deep red
- Streak: Purplish red
- Cleavage: Distinct on {1011}; very imperfect on {0112}
- Fracture: Conchoidal to uneven; brittle
- Value ladder: 4/9 step, Fine dimension stone and ore
- Last checked: 2026-10-04

Proustite's dark red twin: an important silver ore whose name comes from the Greek for “fire” and “silver”.

Pyrargyrite is a mineral made of silver, antimony and sulfur (Ag₃SbS₃). Because of its deep red, adamantine crystals it is also called “dark red silver ore” or “ruby silver”. It is an important silver ore. It has the same structure as proustite; the difference is that proustite contains arsenic and pyrargyrite antimony. E. F. Glocker named it in 1831 from the Greek for “fire” and “silver”, after its colour and composition.

## How does it form?

Pyrargyrite is a primary mineral formed late and at low temperature in veins left by hot water solutions (hydrothermal fluids) moving through cracks; it can also form by secondary processes. It occurs with native silver, acanthite, tetrahedrite and other silver sulfosalts, together with calcite, dolomite and quartz. Its composition can grade into that of proustite.

According to the Handbook of Mineralogy, its known localities include Sankt Andreasberg and Freiberg in Germany, Hiendelaencina in Spain, Jáchymov and Příbram in Czechia, the Comstock Lode in the USA, Colquechaca in Bolivia, Fresnillo and Guanajuato in Mexico, Chañarcillo in Chile and Broken Hill in Australia.

## What is it used for?

- **Silver ore:** It is an important source of silver; silver sulfide minerals are concentrated by flotation.
- **Collecting:** Its deep red, lustrous crystals are sought by collectors.

## How to recognise it

- Deep red, adamantine and translucent; its crystals are often striated.
- Its streak is purplish red, an easy way to tell it from proustite, which leaves a scarlet streak.
- Soft (Mohs 2.5) and heavy (specific gravity about 5.8).
- It darkens on exposure to light.
- Usually found with native silver, acanthite, tetrahedrite, calcite and quartz.

## Fakes and imitations

- Proustite (light red silver ore) is very similar; proustite, however, leaves a scarlet streak and pyrargyrite a purplish-red one.
- Cinnabar is also red and leaves a red streak, but it is a mercury mineral, not a silver one. A certain identification takes analysis.

## What determines its value?

Pyrargyrite is an important silver ore: about 60% of the weight of pure pyrargyrite is silver. It is not uncommon in oxidised silver deposits but rare as fine specimens. Collectors look for deep red, lustrous, sharp and undarkened crystals; because it darkens in light, it is stored in the dark.

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

## Myths and misconceptions

- Myth: Pyrargyrite is named for melting in fire. Fact: The name comes from the Greek for “fire” and “silver”, but it refers not to melting in fire but to the mineral's fiery red colour and the silver it contains.

## Curious questions

**How can proustite and pyrargyrite be told apart?**

Both are red silver minerals of the same structure, known as “ruby silver”. The easiest difference is the streak: on unglazed porcelain proustite leaves a scarlet streak and pyrargyrite a purplish-red one. In composition, proustite contains arsenic and pyrargyrite antimony.

## Did you know?

- Its name comes from the Greek pyr (fire) and argyros (silver), referring to both its colour and the silver it contains.
- Acanthite, proustite and pyrargyrite are among the few silver minerals that can contain enough silver to be mined.
- Its crystals can grow up to 6 cm.

## Where is it found?

- Sankt Andreasberg, Harz Mountains, Germany (Historic source): One of the main classic sources of well-formed crystals
- Himmelsfürst mine, Brand-Erbisdorf (near Freiberg), Saxony, Germany (Historic source): A famous mine of the Freiberg silver district
- Hiendelaencina, Guadalajara, Spain (Known locality): Spanish silver mines that yielded fine specimens
- Guanajuato, Mexico (Major deposit): One of the main sources of well-formed crystals; Fresnillo in Mexico is also known
- Příbram, Central Bohemia, Czechia (Historic source): Silver-bearing lead mines worked for centuries

## Sources

- [Pyrargyrite](https://en.wikipedia.org/wiki/Pyrargyrite), Wikipedia
- [Handbook of Mineralogy: Pyrargyrite](https://www.handbookofmineralogy.org/pdfs/pyrargyrite.pdf), Mineralogical Society of America
- [Dünyada ve Türkiye'de Gümüş (Maden Serisi)](https://www.mta.gov.tr/v3.0/sayfalar/bilgi-merkezi/maden-serisi/dunyada-ve-turkiyede-gumus.pdf), MTA Genel Müdürlüğü


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