THE GEMHOOD EDITORIAL LIBRARY
Proustite gemstone guide
Proustite — silver arsenic sulfosalt mineral. Read about characteristic appearance, Mohs hardness, safety and care.
Gem facts · Quality considerations · Care & meaning
A study in colour and character
Every shade has a story.
Typical appearances for Proustite. Natural stones vary, and lighting or treatment can change their appearance.
Where Proustite is found
Jáchymov, Czech Republic; Freiberg, Germany; Chañarcillo, Chile
Czech Republic
Germany
Chile
How it forms
Forms in silver-bearing hydrothermal veins and related sulfosalt assemblages.
These are representative geological or commercial sources, not certified provenance for an individual stone. Country of origin should be substantiated independently when relevant to value.
01 / THE GEM AT A GLANCE
What is Proustite?
Proustite is silver arsenic sulfosalt mineral, commonly represented by the formula Ag₃AsS₃. Mohs hardness: 2–2.5. Reported colours include Scarlet red to deep red and reddish-grey. Forms in silver-bearing hydrothermal veins and related sulfosalt assemblages. Ruby-red slender trigonal or prismatic crystals, sometimes rich red translucent edges, and progressive darkening on light exposure.
Composition: Ag₃AsS₃. Scientific properties apply to the mineral or gem type, not as a guarantee about an untested individual product.
Proustite is silver arsenic sulfosalt mineral, commonly represented by the formula Ag₃AsS₃. Mohs hardness: 2–2.5. Reported colours include Scarlet red to deep red and reddish-grey. Forms in silver-bearing hydrothermal veins and related sulfosalt assemblages. Ruby-red slender trigonal or prismatic crystals, sometimes rich red translucent edges, and progressive darkening on light exposure. Characteristic features: Ruby-red slender trigonal or prismatic crystals, sometimes rich red translucent edges, and progressive darkening on light exposure. Documented occurrences include Jáchymov, Czech Republic; Freiberg, Germany; Chañarcillo, Chile. Localities describe geological reports, not the proven origin of any individual sale item. Named for chemist Joseph-Louis Proust and historically grouped with so-called ruby silver ores. Collector-only specimen, not safe or durable for wearable crystal products; contains arsenic and silver. Keep in dark enclosed display; minimize handling, do not make dust and wash hands afterwards. Distinguish proustite from pyrargyrite and cinnabar by scientific tests; colour and “ruby silver” trade labels are not enough. Contains arsenic, is soft and light-sensitive; never use in water infusions or wellness products. Specialist testing and chain-of-custody evidence matter for high-value or hazardous materials. Genuine mineral identification requires evidence beyond colour or the appearance of a picture. Read the complete guide before acquiring a specimen.
02 / LOOK CLOSER
Colour, appearance and quality
Characteristic features: Ruby-red slender trigonal or prismatic crystals, sometimes rich red translucent edges, and progressive darkening on light exposure. Documented occurrences include Jáchymov, Czech Republic; Freiberg, Germany; Chañarcillo, Chile. Localities describe geological reports, not the proven origin of any individual sale item.
Before you choose a stone
Compare images taken in more than one lighting condition, ask for views of the actual item and check how the cut and setting change its appearance. A gemstone type is not a standard grade: each natural specimen has its own colour, inclusions and workmanship.
THE GEMHOOD BUYER'S FIELD NOTES
How to choose Proustite: three checks
- 01
Distinguish proustite from pyrargyrite and cinnabar by scientific tests; colour and “ruby silver” trade labels are not enough.
- 02
Keep in dark enclosed display; minimize handling, do not make dust and wash hands afterwards.
Contains arsenic, is soft and light-sensitive; never use in water infusions or wellness products.
Collector-only specimen, not safe or durable for wearable crystal products; contains arsenic and silver.
These notes describe typical gem material and trade practices. They do not independently grade or identify a specific item offered for sale.
03 / BUY WITH CONFIDENCE
Natural, laboratory-grown, treated or imitation?
Distinguish proustite from pyrargyrite and cinnabar by scientific tests; colour and “ruby silver” trade labels are not enough. Contains arsenic, is soft and light-sensitive; never use in water infusions or wellness products. Specialist testing and chain-of-custody evidence matter for high-value or hazardous materials.
These distinctions should be clear in the listing for any particular gem. Treatments are not automatically unacceptable, but an undisclosed treatment, vague mineral identity or unsupported origin claim prevents an informed purchase. Where material identity materially affects value, an independent gemological identification report may be worth considering.
A CLOSER LOOK
Formation and mineral chemistry
Forms in silver-bearing hydrothermal veins and related sulfosalt assemblages.
Proustite is silver arsenic sulfosalt mineral, commonly represented by the formula Ag₃AsS₃. Mohs hardness: 2–2.5. Reported colours include Scarlet red to deep red and reddish-grey. Forms in silver-bearing hydrothermal veins and related sulfosalt assemblages. Ruby-red slender trigonal or prismatic crystals, sometimes rich red translucent edges, and progressive darkening on light exposure.
A CLOSER LOOK
Diagnostic features and lookalikes
Ruby-red slender trigonal or prismatic crystals, sometimes rich red translucent edges, and progressive darkening on light exposure.
Distinguish proustite from pyrargyrite and cinnabar by scientific tests; colour and “ruby silver” trade labels are not enough.
A CLOSER LOOK
Representative origins and provenance
Jáchymov, Czech Republic; Freiberg, Germany; Chañarcillo, Chile
A locality reference does not prove the offered specimen originates there.
A CLOSER LOOK
Uses and jewellery suitability
Collector-only specimen, not safe or durable for wearable crystal products; contains arsenic and silver.
Contains arsenic, is soft and light-sensitive; never use in water infusions or wellness products.
A CLOSER LOOK
Cleaning, handling and storage
Keep in dark enclosed display; minimize handling, do not make dust and wash hands afterwards.
Named for chemist Joseph-Louis Proust and historically grouped with so-called ruby silver ores.
A CLOSER LOOK
Specimen image attribution and reuse licence
Specimen image adapted from 'Proustite 1.jpg' by Parent Géry on Wikimedia Commons. Licence: Public domain (author dedication). Photo has been resized, converted to WebP and presented against a white background.
Original source: https://commons.wikimedia.org/wiki/File:Proustite_1.jpg ; licence text: https://creativecommons.org/publicdomain/mark/1.0/. The image licence applies to this derivative, not the entire GemHood website.
04 / WEAR IT WELL
Proustite in jewellery
Collector-only specimen, not safe or durable for wearable crystal products; contains arsenic and silver.
05 / MAKE IT LAST
How to care for Proustite
Keep in dark enclosed display; minimize handling, do not make dust and wash hands afterwards.
One essential care distinction
Mohs hardness describes resistance to scratching, not resistance to breaking. Gemstones with cleavage, existing fractures, porous surfaces or fillings can need extra care regardless of their hardness number. If you do not know whether a piece has been treated, begin with the gentlest appropriate cleaning method.
06 / CULTURE & MEANING
History, heritage and symbolism
Named for chemist Joseph-Louis Proust and historically grouped with so-called ruby silver ores.
Traditional meanings and spiritual associations are part of cultural storytelling. They are not evidence that a gemstone diagnoses, prevents or treats any medical condition.
GOOD QUESTIONS, CLEAR ANSWERS
Proustite FAQs
What is Proustite?
Proustite is silver arsenic sulfosalt mineral, commonly represented by the formula Ag₃AsS₃. Mohs hardness: 2–2.5. Reported colours include Scarlet red to deep red and reddish-grey. Forms in silver-bearing hydrothermal veins and related sulfosalt assemblages. Ruby-red slender trigonal or prismatic crystals, sometimes rich red translucent edges, and progressive darkening on light exposure.
What is the Mohs hardness of Proustite?
2–2.5; scratch hardness does not measure toughness or safety.
Where is Proustite found?
Jáchymov, Czech Republic; Freiberg, Germany; Chañarcillo, Chile. Individual provenance must be independently verified.
Is Proustite suitable for jewellery?
Collector-only specimen, not safe or durable for wearable crystal products; contains arsenic and silver.
How should I store and clean Proustite?
Keep in dark enclosed display; minimize handling, do not make dust and wash hands afterwards.
How can I identify genuine Proustite?
Distinguish proustite from pyrargyrite and cinnabar by scientific tests; colour and “ruby silver” trade labels are not enough.
What safety or treatment issues affect Proustite?
Contains arsenic, is soft and light-sensitive; never use in water infusions or wellness products.
A NOTE FROM THE GEMHOOD EDITORIAL DESK
How to use this guide
We explain gemstone properties, known mining regions and customary treatments to help you shop more confidently. Each gemstone can vary in quality and individual provenance, so compare the actual jewellery listing and request supporting documentation if origin, treatment or natural-versus-laboratory-grown status affects your choice.
Our gemstone library is educational and does not act as a laboratory identification certificate. Independent gemological assessment is advisable for valuable or disputed claims.
EDITORIAL REFERENCES
Research and further reading
References describe mineral species and representative occurrences, not verification of any individual item for sale.
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Compare Proustite with similar gemstones
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KEEP EXPLORING
Other gemstones to discover
Educational articles describe gemstone types and common trade practices. They are not individual gemological certificates, current price appraisals or medical advice.