Search: 991 results found for "pyrite"

Pyrite on Dolomite Mineral Specimen 6.3cm Tali & Loz Crystals

Pyrite on Dolomite Mineral Specimen | 140g

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£35.00

Pyrite Tumblestones 15-25mm

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£4.00

Pyrite In Serpentine Towers, Intuitively Chosen

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£27.00

Amethyst & Pyrite Specimen | 70mm | Chala Mine, Bulgaria

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£120.00

Turquoise with Pyrite 3.2cm | Morenci, Arizona, USA

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£72.00

Pyrite Pseudomorph after Pyrrhotite Specimen 1KG, Trepca Yugoslavia Specimen Tali & Loz Crystals

Pyrite Pseudomorph after Pyrrhotite Specimen | 1kg | Trepča, Yugoslavia

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£250.00

Kutnahorite Specimen with Pyrite | 5.1cm | Pachapaqui, Peru

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£90.00

Ammonite From Madagascar with Pyrite 10.5cm

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£45.00

Confidence Crystal Gift Set

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£10.00

Australian Broken Hill Tumblestones 20-30mm

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£4.00

Rough Blue Hackmanite with Pyrite Rough Crystals Tali & Loz Crystals

Blue Hackmanite | 2cm | Pakistan

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£12.00

Lapis Lazuli Cabochon | 2.4cm | Afghanistan

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£14.00

Lapis Lazuli Cabochon | 1.1cm | Afghanistan

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£15.00

Lapis Lazuli Egg | 0.6kg | Madani, Afghanistan

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£95.00

Lapis Lazuli Shiva | 6.5cm | Afghanistan

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£45.00

Taurus Zodiac Crystal Set

(2)

£12.00

Lapis Lazuli Egg | 1.1kg | Madani, Afghanistan

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£125.00

Lapis Lazuli Eggs | 4.5cm | India

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£14.00

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Pyrite: The Mineral That Fooled the World and Still Fascinates It

What is Pyrite? Mineral Group: Sulphide | Category: Iron Sulphide | Formula: FeS₂ | Hardness: 6 to 6.5 (Mohs) Pyrite is an iron sulphide mineral (FeS₂) and one of the most abundant and widely distributed sulphide minerals on Earth. It is immediately recognisable by its brassy, metallic gold colouration and tendency to form geometrically precise cubic, octahedral, or pyritohedral crystals, a habit so distinctive that it has made Pyrite one of the most recognisable minerals in both scientific and collector contexts. Its popular name, Fool's Gold, reflects a long history of mistaken identity. Prospectors throughout history, particularly during the gold rushes of the 18th and 19th centuries, regularly confused Pyrite with native Gold due to their similar colour and metallic lustre. The two minerals are in fact straightforward to distinguish: Gold is considerably denser, softer, and does not produce a greenish-black streak when drawn across an unglazed ceramic surface, while Pyrite does. The name Pyrite derives from the Greek word pyr, meaning fire, a reference to the sparks produced when Pyrite is struck against iron or steel. This property was exploited practically for centuries, from ancient fire-starting tools to the mechanisms of early firearms. How Does It Form? Pyrite forms in an exceptionally wide range of geological environments, which accounts for its abundance and global distribution. It crystallises from sulphur-rich hydrothermal fluids within veins and fractures in igneous, metamorphic, and sedimentary rocks. It also forms through low-temperature processes in sedimentary environments, particularly in marine muds and shales where organic matter creates reducing conditions that favour iron sulphide precipitation. In hydrothermal settings, iron and sulphur-rich fluids moving through the crust cool and deposit Pyrite alongside other sulphide and oxide minerals, including Galena and Quartz. This is the environment that produces the large, well-formed cubic and octahedral crystals most prized by collectors, with some of the finest examples coming from Navajún in Spain, where perfectly formed cubic Pyrite crystals up to several centimetres across occur in a matrix of clay-rich sedimentary rock. In sedimentary environments, Pyrite forms through bacterial sulphate reduction, a process by which sulphate-reducing bacteria break down organic matter in oxygen-poor conditions, releasing sulphide that combines with iron in the surrounding sediment. Pyrite is also a common accessory mineral in coal deposits and is frequently found replacing organic material in fossils, producing the distinctive golden fossilised shells and ammonites often encountered in collector markets. Notable sources of fine Pyrite specimens include Spain, Peru, Russia, the United States, and Italy. Key Physical Properties at a Glance Property Detail Chemical Formula FeS₂ (Iron Sulphide) Crystal System Isometric (Cubic) Hardness 6 to 6.5 (Mohs) Specific Gravity 4.95 to 5.10 Lustre Metallic Streak Greenish-black to brownish-black Fracture Uneven Cleavage Poor Safe to Cleanse in Water No Pyrite's specific gravity of 4.95 to 5.10 is notably high, reflecting its dense iron sulphide chemistry. The striations commonly visible on Pyrite crystal faces (known as striation marks) result from the repeated twinning of crystal faces during growth and are particularly pronounced on cubic specimens. They are absent on Gold, providing a useful distinguishing characteristic. Crystal Habits and Why Pyrite Grows the Way It Does Pyrite's tendency to form geometrically precise crystals is one of its most scientifically interesting characteristics. It crystallises in the isometric system, meaning its internal atomic arrangement has equal symmetry in all three dimensions. This symmetry is directly expressed in the external crystal form, producing the cubes, octahedra, and pyritohedra (twelve-faced forms with pentagonal faces) that make Pyrite specimens so visually striking. The pyritohedral form is particularly notable because its pentagonal faces display a subtle but measurable deviation from perfect symmetry, related to the way iron and sulphur atoms are arranged within the crystal structure. This makes Pyrite one of relatively few common minerals whose crystal habit directly reflects a structural asymmetry invisible to the naked eye. The cubic Pyrite specimens from Navajún, Spain, are exceptional examples of isometric crystal growth, forming as isolated, perfectly formed cubes within a soft clay matrix with virtually no matrix attachment distortion. They are among the most geometrically precise natural crystals known. Pyrite and Marcasite: Understanding the Difference Pyrite has a polymorph (a mineral with the same chemical composition but a different crystal structure) called Marcasite. Both are iron sulphide (FeS₂), but Marcasite crystallises in the orthorhombic system rather than the isometric system, producing distinctly different crystal habits including flat, tabular, or cockscomb-shaped aggregates. Marcasite is less stable than Pyrite at surface conditions and is prone to pyrite disease, where exposure to moisture and oxygen causes the mineral to oxidise and break down, producing sulphuric acid and iron sulphate compounds that can physically destroy specimens over time. For collectors, the distinction matters: if a specimen begins to show white powdery deposits, a sulphurous smell, or physical crumbling, it is likely Marcasite rather than true Pyrite, and should be stored in dry, sealed conditions to slow deterioration. Pyrite Disease and Long-Term Stability True Pyrite is considerably more stable than Marcasite but is not entirely immune to oxidative deterioration under poor storage conditions. When exposed to sustained moisture and oxygen, Pyrite can slowly oxidise to produce iron sulphate minerals and sulphuric acid, manifesting as white or yellow powdery surface deposits and a faint sulphurous odour. This is why water cleansing is not recommended for Pyrite. Store Pyrite in dry conditions, away from sustained humidity, and clean with a dry soft cloth only. Museum collections routinely store Pyrite specimens in sealed, desiccated environments to maximise long-term stability. For guidance on safe cleansing methods for all your crystals, see our full guide: How to Cleanse and Recharge Your Crystals. Traditional Associations While this guide focuses on the mineralogy of Pyrite, it is widely used in spiritual and wellbeing practices. It is traditionally associated with confidence, abundance, vitality, and manifestation, and is commonly linked to the Solar Plexus Chakra and Third Eye Chakra in crystal healing systems. These associations are rooted in cultural and traditional use rather than scientific properties. For a full exploration of how to work with Pyrite spiritually, see our dedicated guide: Best Crystals for Confidence. Shop Pyrite Explore our collection of Pyrite specimens, from raw clusters to polished forms, each piece selected for quality and character. Summary Pyrite is one of Earth's most abundant and geologically versatile sulphide minerals, forming in environments ranging from deep hydrothermal veins to shallow marine sediments. Its distinctive gold colouration, precise geometric crystal habits, and historically significant fire-producing properties have made it one of the most recognised minerals in human history. For collectors, it offers outstanding crystal specimens, fascinating polymorphic chemistry, and a direct connection to some of the most important geological processes on the planet. For general buyers, it is a bold, metallic, and geologically compelling mineral whose story extends far beyond the Fool's Gold nickname it has carried for centuries. As always, our inbox and DMs are open if you would like guidance or simply wish to explore further. Contact us Love, Laura Further Reading Explore more from The Crystal & Mineral Vault and our wider guides: Permineralized Wood Mineral Guide Hematite Mineral Guide Citrine: Bask in the Golden Radiance of Citrine's Abundant Energy Best Crystals for Confidence Crystals and Sacred Geometry How to Choose the Right Crystals Based on Their Shapes

on Jan 17 2025

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Chalcopyrite: The Copper Ore Behind Modern Electricity

What is Chalcopyrite? Mineral Group: Sulphide | Category: Copper Iron Sulphide | Formula: CuFeS₂ | Hardness: 3.5 – 4 (Mohs) Chalcopyrite is a copper iron sulphide mineral and the most important copper ore mineral on Earth. More copper has been extracted from Chalcopyrite than from any other mineral source, and it underpins the global copper supply that makes modern electrical infrastructure, electronics, and construction possible. To a collector it is known equally for its striking brass-yellow colour in fresh specimens and for the vivid iridescent tarnish, a peacock-like display of blues, purples, golds, and greens, that develops on weathered surfaces and gives it the widely used commercial name Peacock Ore. The name Chalcopyrite derives from the Greek chalkos, meaning copper, and pyrites, meaning fire or related to fire, the same root that gives us Pyrite. The fire reference reflects the sparks produced when iron-bearing sulphide minerals are struck against flint or steel, a property that made these minerals practically significant to ancient cultures long before their chemistry was understood. Chalcopyrite has been recognised as a copper source since antiquity, and the smelting of copper from Chalcopyrite-bearing ores has been documented archaeologically to at least 5000 BCE. Chalcopyrite belongs to the sulphide mineral group, defined by the presence of sulphur bonded to one or more metal cations. The sulphide group encompasses many of the most economically important ore minerals, including Galena, Sphalerite, Molybdenite, and Pyrite, as well as some of the most visually striking minerals in any collection. Formation and Geological Context Chalcopyrite forms in a wide range of geological environments, which is part of what makes it such an abundant and economically significant mineral. Its primary occurrence is in hydrothermal ore deposits, where hot, metal-rich fluids circulate through the crust and deposit sulphide minerals as they cool. The porphyry copper deposit type, in which Chalcopyrite and associated copper sulphides are disseminated through large volumes of altered igneous rock, accounts for the majority of global copper production and represents some of the largest ore deposits on Earth. Chalcopyrite also occurs in volcanogenic massive sulphide deposits, formed at ancient and modern seafloor hydrothermal vents where metal-rich fluids emerge into cold seawater and precipitate dense accumulations of sulphide minerals. Contact metasomatic deposits, called skarns, formed where igneous intrusions interact with carbonate rocks, are another significant setting. In metamorphic environments, earlier-formed Chalcopyrite can be remobilised and recrystallised into new structural settings. In the oxidised zones of copper deposits, where Chalcopyrite is exposed to weathering, it breaks down to produce secondary copper minerals including Malachite, Azurite, Chrysocolla, and Cuprite, the vivid green and blue minerals often found associated with Chalcopyrite in collections. The Chalcopyrite itself is the geological parent of these secondary minerals, making it the source of some of the most visually striking minerals in the copper family. Notable localities for collector-quality Chalcopyrite include Freiberg in Germany, Cornwall in England, Treпča in Kosovo, various localities in Mexico and Peru, and the vast porphyry copper systems of Chile and the American Southwest where mining operations expose exceptional crystal specimens. Key Physical Properties Property Detail Mineral Group Sulphide Category Copper Iron Sulphide Crystal System Tetragonal Hardness 3.5 – 4 Mohs Specific Gravity 4.10 – 4.30 Refractive Index 2.87 – 3.10 Birefringence 0.230 Pleochroism Weak Lustre Metallic Fracture Subconchoidal to uneven Cleavage Indistinct Tenacity Brittle Colour Brass-yellow, iridescent tarnish Streak Greenish black Formula CuFeS₂ Safe to Cleanse in Water No The specific gravity of 4.10 to 4.30 is considerably higher than most silicate minerals, reflecting the density of the copper and iron sulphide structure. The diagnostic greenish-black streak distinguishes Chalcopyrite from Pyrite, which produces a greenish-black to black streak, and from Gold, which produces a golden yellow streak: this streak test is one of the quickest and most reliable ways to identify Chalcopyrite in the field. The metallic lustre is characteristic of sulphide minerals and gives fresh Chalcopyrite its bright, mirror-like brass surface. The Iridescent Tarnish: Peacock Ore and the Physics of Colour The iridescent surface that gives Chalcopyrite the commercial name Peacock Ore is one of the most visually striking effects seen on any mineral surface, and understanding how it forms adds considerable depth to what might otherwise seem a purely decorative feature. Fresh Chalcopyrite surfaces are bright brass-yellow and highly reflective, with a metallic lustre that superficially resembles gold or Pyrite. When exposed to air and moisture, the surface begins to oxidise, producing a thin oxide and hydroxide film that grows progressively thicker over time. This film is transparent to light but has a different refractive index from both the Chalcopyrite beneath it and the air above it. As light strikes the tarnished surface, part of it reflects from the top of the film and part passes through to reflect from the Chalcopyrite surface below. These two reflected beams travel different path lengths and interfere with each other, either constructively, amplifying certain wavelengths, or destructively, cancelling others. The specific wavelength amplified depends on the thickness of the film at that point: thinner films produce blue and violet, thicker films produce gold and green, and intermediate thicknesses produce every colour in between. This is the same thin-film interference mechanism that produces the colours of oil films on water, soap bubbles, and the labradorescence of Labradorite. In Chalcopyrite the film grows at different rates across different parts of the surface depending on local variations in surface chemistry and exposure to air and moisture, producing a mosaic of different thicknesses and therefore a mosaic of different colours simultaneously. The result is the vivid, shifting multicolour display that makes Peacock Ore so visually compelling. It is worth noting that some commercial Peacock Ore specimens have been acid-treated to artificially intensify or produce the iridescent colours on material that would otherwise show minimal tarnish. Naturally tarnished Chalcopyrite and acid-treated material are both genuine Chalcopyrite but represent different states of the mineral’s surface chemistry. Natural tarnish tends toward more subtle, evenly distributed colour, while acid-treated material often shows more extreme and patchy colour saturation. Chalcopyrite and Its Confusion With Pyrite and Gold Chalcopyrite, Pyrite, and Gold are sufficiently similar in appearance to have caused confusion among prospectors and collectors throughout history, and the distinctions between them are worth understanding clearly. All three are metallic-lustre minerals in the yellow to gold colour range. Gold is the densest of the three by a considerable margin, with a specific gravity of approximately 19.3 compared to Chalcopyrite’s 4.1 to 4.3 and Pyrite’s 4.9 to 5.2. The heft test, simply picking up a specimen and feeling its weight relative to its size, is therefore a rapid and reliable preliminary distinction: gold feels dramatically heavier than either sulphide for any given volume. The streak test provides the most reliable rapid identification. Gold produces a golden yellow streak. Pyrite produces a greenish-black to black streak. Chalcopyrite produces a greenish-black streak similar to Pyrite but distinguishable in good light. The colour of the fresh mineral surface also differs subtly: Gold is a richer, warmer yellow, Pyrite is a paler, more silvery yellow, and Chalcopyrite has a distinctly brassy, slightly greenish-yellow tone. Hardness provides another distinction: Gold is soft at hardness 2.5 to 3 and can be marked with a copper coin, while Chalcopyrite at 3.5 to 4 is harder and Pyrite at 6 to 6.5 is considerably harder than either. Pyrite also tends to form more perfectly geometric cubic or pyritohedral crystals than Chalcopyrite. Chalcopyrite as a Copper Ore The economic significance of Chalcopyrite extends well beyond its role as a collector mineral, and understanding its industrial importance gives context to its geological occurrence and the scale of mining operations associated with it. Chalcopyrite contains approximately 34.5 percent copper by weight, making it a moderately rich copper ore. The extraction of copper from Chalcopyrite is more complex than from native copper or from higher-grade secondary minerals such as Malachite, requiring pyrometallurgical smelting or hydrometallurgical leaching processes. Despite this complexity, the sheer abundance of Chalcopyrite in large porphyry copper deposits makes it the dominant source of copper globally, contributing the majority of the approximately 22 million tonnes of copper produced worldwide each year. Copper extracted from Chalcopyrite underpins the electrical systems of modern civilisation. Electrical wiring, power generation and transmission infrastructure, electric motors, electronics, and the batteries and wiring of electric vehicles all depend on copper, and the growth of renewable energy and electric vehicle technology has increased global copper demand significantly. The geological deposits that contain Chalcopyrite are therefore not merely mineralogical curiosities but critical resources for the transition to low-carbon energy systems. Toxicity and Safety Chalcopyrite contains both copper and iron within a sulphide matrix, and basic safety awareness is appropriate for handling and storing specimens. Solid Chalcopyrite specimens are safe for normal display and careful handling. The copper and iron are locked within the sulphide crystal structure and do not leach from solid material under normal conditions. However the greenish-black streak and oxidation products of Chalcopyrite can contain copper compounds that are mildly toxic, and hands should be washed after handling as a routine precaution. Water cleansing should be avoided. Sulphide minerals in contact with water and oxygen can generate sulphuric acid through oxidation reactions, a process that damages the specimen surface and produces mildly acidic, copper-bearing solutions that are not suitable for contact with skin or disposal without care. Keep specimens dry and clean with a soft dry cloth only. Chalcopyrite dust generated by cutting or grinding should not be inhaled: copper compounds are toxic if inhaled and appropriate respiratory protection should be used for any working of the material. Traditional Associations While this guide focuses on the mineralogy and science of Chalcopyrite, it is valued in spiritual and mindful practices for its associations with abundance, transformation, and enhanced perception. Its vivid iridescent surface has made it a popular choice for practices focused on positive change, manifestation, and inner vision. In chakra work it is connected to the Crown, Third Eye, and Solar Plexus Chakras. These associations are rooted in cultural and traditional use rather than scientific properties. For a full exploration of how to work with Chalcopyrite spiritually, see our dedicated spiritual guide. Summary Chalcopyrite is a copper iron sulphide mineral and the world’s primary copper ore, its economic significance extending from ancient Bronze Age smelting to the electrical infrastructure and battery technology of the modern world. Its brass-yellow fresh surface and vivid iridescent tarnish, produced by the same thin-film interference mechanism that colours soap bubbles and Labradorite, make it one of the more visually dynamic sulphide minerals available to collectors. Understanding the chemistry of its tarnish, its distinctions from Pyrite and Gold, the geological environments that concentrate it, and the basic safety considerations for handling sulphide minerals gives a complete picture of a mineral that is simultaneously one of the most economically important and one of the most visually compelling in any collection. Browse our full Chalcopyrite collection to find natural specimens, tarnished Peacock Ore pieces, and matrix examples. As always, our inbox and DMs are open if you would like guidance or simply wish to explore further. Contact us Love, Laura Further Reading Pyrite: The Mineral That Fooled the World and Still Fascinates It Malachite: From Ancient Egyptian Cosmetics to the Winter Palace Azurite: The Mineral That Coloured Medieval Paintings Chrysocolla: Express Your Truth with Serenity Labradorite: The Stone the Inuit Called Frozen Aurora A Beginner’s Guide to Mineral Chemical Properties and Classification A Beginner’s Guide to Mineral Physical Properties

on Mar 15 2025

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