Search: 113 results found for "turquoise"

Turquoise Rough | 1-2cm | Kingman Mine, Arizona, USA

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£8.00

Turquoise Rough | 2-3cm | Kingman Mine, Arizona, USA

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£12.00

Turquoise Rough | 3-4cm | Kingman Mine, Arizona, USA

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£16.00

Turquoise with Pyrite 3.2cm | Morenci, Arizona, USA

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£72.00

Aquamarine Specimen 4gr, Sold as Seen

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£65.00

Chrysocolla Flame 7.2cm, Peru

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£27.00

Chrysocolla Tumblestones | 28-36mm | Peru

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£5.00

Malacholla Slab 9cm

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£75.00

Aquamarine Specimen 15.7gr, Sold as Seen Specimen Tali & Loz Crystals

Aquamarine Specimen | 15.7gr | Pakistan

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£160.00

Amazonite Tumblestones 20-30mm

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£4.00

Amazonite AAA-Grade Chip Bottles 10ml

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£7.50

Chrysocolla on top of Malachite Specimen 1.1KG, Zaire Specimen Tali & Loz Crystals

Chrysocolla on Malachite Specimen | 1.1KG | Zaire

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£220.00

Aquamarine Tumblestones 20-30 mm

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£4.00

Amazonite A-Grade Chip Bottles 10ml

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£6.50

Indicolite Tourmaline with Quartz | 22mm | Brazil

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£35.00

Indicolite Blue Tourmaline | Crystal | 45mm | Brazil

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£350.00

Chalcanthite Specimen | 108mm | Anthropogenic

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£95.00

Blue-Green Bi-Colour Tourmaline | 10.25g | Brazil

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£75.00

Blog

Turquoise: From Tutankhamun's Burial Mask to the American Southwest

What is Turquoise? Mineral Group: Phosphate | Category: Hydrated Copper Aluminium Phosphate | Formula: CuAl₆(PO₄)₄(OH)₈·4H₂O | Hardness: 5 – 6 (Mohs) Turquoise is a hydrated copper aluminium phosphate mineral and one of the oldest gemstones in continuous human use. Its distinctive blue to blue-green coloration, produced by copper within a phosphate framework, has made it recognisable and valued across cultures separated by thousands of miles and thousands of years. From the burial mask of Tutankhamun to the jewellery of the Aztec emperors, from the mosaics of Persian palaces to the silverwork of the American Southwest, Turquoise has a cultural footprint that is matched by very few minerals on Earth. The name derives from the French turquois, meaning Turkish, a reference to the trade routes through which the stone reached medieval Europe from Persian and Central Asian sources via Turkey. The mineral itself was never significantly mined in Turkey, but Turkish merchants were the primary intermediaries through whom European buyers encountered it, and the geographical association stuck in the naming convention. Turquoise belongs to the phosphate mineral group, a classification that places it among a family of minerals defined by the phosphate ion PO₄³⁻ as the dominant anionic complex. It is a relatively rare mineral in geological terms, forming only under a specific and unusual combination of conditions, which is why despite its cultural ubiquity genuinely fine natural Turquoise of top quality is scarcer and more valuable than many casual buyers expect. Formation and Geological Context Turquoise forms through the secondary alteration of existing rocks in arid to semi-arid environments where copper-bearing solutions interact with aluminium-rich host rocks in the presence of phosphate. The process is one of supergene enrichment: primary copper sulphide minerals deposited by hydrothermal activity at depth are oxidised by weathering near the surface, releasing copper ions into the surrounding groundwater. These copper-rich solutions percolate downward through aluminium-bearing rocks, typically feldspar-rich volcanic rocks or sediments, and where phosphate is also available from the breakdown of apatite or other phosphate minerals, the conditions for Turquoise precipitation are established. The formation therefore requires the simultaneous availability of three relatively uncommon geological ingredients: a copper source, an aluminium-rich host rock, and a phosphate supply, all within an oxidising, relatively arid environment where evaporation concentrates the solutions sufficiently for Turquoise to precipitate. This combination of requirements is what makes Turquoise genuinely uncommon geologically despite its cultural familiarity. The same copper-rich oxidising environments also produce related minerals such as Chrysocolla and Azurite,, which are often found in association with Turquoise at the same localities. Turquoise occurs most commonly as veinlets, crusts, and nodular masses filling fractures and cavities in the host rock rather than as well-developed crystals. Distinct, well-formed Turquoise crystals are extremely rare and highly prized by mineralogists. The matrix in which Turquoise occurs, typically the brown to black host rock cut through by blue-green Turquoise veins, is often left attached to collector and jewellery-grade specimens and is part of the visual character of natural material. The most historically and geologically significant Turquoise deposits include those of the Nishapur region in Iran, which has produced the finest blue material for over three thousand years and remains the benchmark for colour quality in the trade. The American Southwest, particularly Arizona, New Mexico, Nevada, and Colorado, is the other major producing region and the source of most Turquoise associated with Native American jewellery traditions. Other notable sources include China, which produces large volumes of material across a wide quality range, Egypt’s Sinai Peninsula where Turquoise was mined as far back as 3200 BCE, and Tibet. Key Physical Properties Property Detail Mineral Group Phosphate Category Hydrated Copper Aluminium Phosphate Crystal System Triclinic Hardness 5 – 6 Mohs Specific Gravity 2.60 – 2.90 Refractive Index 1.61 – 1.65 Birefringence 0.040 – 0.055 Pleochroism Weak to moderate in gem quality material Lustre Waxy to subvitreous Fracture Conchoidal to uneven Cleavage Perfect in one direction Tenacity Brittle Colour Blue, blue-green, greenish-grey Streak White to pale green Formula CuAl₆(PO₄)₄(OH)₈·4H₂O Safe to Cleanse in Water Gentle rinse only; no soaking The wide range of specific gravity, from 2.60 to 2.90, reflects the variability in porosity and the degree of secondary mineralisation between different specimens and localities. Dense, fine-grained material from the best Iranian deposits sits toward the higher end of this range, while more porous material from other sources is lighter. The hardness of 5 to 6, moderate by gemstone standards, combined with the perfect cleavage in one direction, means Turquoise requires more careful handling than harder, cleavage-free gemstones such as Quartz or Chrysoprase. The Colour of Turquoise: Copper, Iron, and the Blue-Green Range The colour of Turquoise is one of its most defining characteristics and one of the more nuanced colour stories in the phosphate mineral family. The fundamental blue coloration is produced by copper in the Cu²⁺ oxidation state within the crystal structure, absorbing in the red and orange parts of the visible spectrum and reflecting blue and blue-green wavelengths. The specific shade, ranging from the pure sky blue of the finest Persian material through to blue-green, green, and grey-green tones, is modified by the balance between copper and iron within the structure. Pure copper with minimal iron substitution produces the most prized sky blue. As iron substitutes progressively for aluminium within the crystal structure the colour shifts toward green, producing the blue-green and greener material that, while still genuine Turquoise, is generally considered less valuable in the gem trade. The greenest material grades toward a related mineral called Faustite, which is the zinc-dominant analogue of Turquoise in which zinc rather than copper occupies the relevant structural sites, producing distinctly green rather than blue tones. Variscite is another green phosphate sometimes confused with green Turquoise but is an aluminium phosphate without copper and therefore lacks the blue component entirely. The waxy to subvitreous lustre of Turquoise is characteristic and arises from the microcrystalline to fine-grained texture of most natural material. High-lustre, more vitreous surfaces are associated with the finest, densest material. Turquoise, Treatments, and the Market Turquoise is one of the most heavily treated gemstones in the commercial market, and understanding the range of treatments is essential for any buyer or collector. Natural untreated Turquoise of gem quality is genuinely scarce. The majority of commercial Turquoise has been stabilised, a process in which the porous natural material is impregnated with a colourless resin or polymer under pressure to harden it, improve its colour consistency, and make it suitable for cutting and polishing. Stabilised Turquoise is natural Turquoise that has been treated: the mineral itself is genuine, but the porosity has been filled and the surface hardened. This is widely accepted in the trade and is appropriate when disclosed. Enhanced Turquoise has been impregnated with coloured resin to improve or alter its colour as well as harden it. This is a more significant treatment than stabilisation and affects the colour of the material directly. Simulants include dyed Howlite, a white calcium borosilicate mineral that accepts dye readily and produces a convincing visual imitation of Turquoise at a fraction of the cost. Dyed Magnesite and various dyed chalks are also sold as Turquoise simulants. These are not Turquoise at all and should be sold as imitations rather than as the genuine mineral. Synthetic Turquoise, produced by various processes to replicate the chemistry and appearance of natural material, also exists in the market. For collectors and buyers, the practical guidance is straightforward: ask specifically whether material is natural, stabilised, enhanced, or simulated, and buy from sources that provide clear answers. Genuine natural untreated Turquoise of fine quality from known localities commands significant premiums and is worth understanding as a distinct category from stabilised commercial material. Colour Change and Long-Term Stability Turquoise is known to change colour over time, and this is worth understanding clearly for anyone wearing or collecting the mineral. The colour change is primarily a result of the porosity of natural and stabilised Turquoise absorbing substances from its environment. Oils from skin, perfumes, cosmetics, sunscreens, and cleaning products can all penetrate the surface of porous Turquoise and alter its colour, typically shifting it toward green or grey. This is an irreversible chemical change rather than a surface stain in most cases. Prolonged exposure to strong sunlight can also cause gradual fading of the blue coloration through photochemical degradation of the copper chromophore. This colour sensitivity has cultural significance in some traditions, where the colour change of a Turquoise stone was interpreted as a protective response or an indicator of the wearer’s health. The scientific explanation is less romantic but more useful: the mineral is responding chemically to its environment, and the direction of change is determined by what it has been exposed to. Protecting Turquoise from oils, chemicals, and sustained UV exposure will preserve its colour for longer. Dense, high-quality natural Turquoise and well-stabilised material are less susceptible to colour change than porous lower-grade natural material. Turquoise in Human History The human relationship with Turquoise is among the oldest and most geographically diverse of any gemstone, predating written history in multiple regions simultaneously. The Sinai Peninsula deposits of Egypt were being mined for Turquoise as early as 3200 BCE, making them among the earliest documented gemstone mines in the world. Turquoise is found throughout ancient Egyptian jewellery and funerary objects: the famous pectoral collar of Tutankhamun incorporates Turquoise alongside Lapis Lazuli and Carnelian in one of the most celebrated examples of ancient gemstone work. The Egyptians called it mefkat, associated it with joy and fertility, and used it in amulets and inlay work across more than three thousand years of dynastic history. In Persia, the Nishapur deposits produced the finest sky blue material and Turquoise became deeply woven into Persian artistic and cultural identity. Persian craftsmen used it extensively in architectural tilework, jewellery, and decorative objects, and the intense blue of Persian Turquoise became the benchmark colour standard that the trade still references. In pre-Columbian Mesoamerica, Turquoise held ceremonial and political significance among the Aztec, Maya, and other cultures. The Aztec mosaic masks and shields incorporating Turquoise, several of which survive in museum collections, represent some of the most technically accomplished examples of Turquoise inlay work ever produced. In North America, the relationship between Turquoise and the Indigenous cultures of the Southwest, particularly the Navajo, Zuni, and Pueblo peoples, is among the deepest and most enduring in the mineral’s history. Turquoise has been mined, traded, and worked in this region for over a thousand years, and the tradition of combining Turquoise with silver in jewellery, while the silversmithing itself developed in the nineteenth century, draws on a Turquoise working tradition of far greater antiquity. Care and Handling Turquoise requires more careful handling than most gemstones of comparable hardness due to its porosity, colour sensitivity, and perfect cleavage. The most important care rule is to keep it away from chemicals, oils, and prolonged water exposure. A gentle rinse under lukewarm water is acceptable for cleaning, followed immediately by patting dry with a soft cloth. Never soak Turquoise: prolonged water exposure can be absorbed into porous material and affect both the structure and the colour over time. Avoid contact with perfumes, cosmetics, sunscreens, and cleaning products entirely. Remove Turquoise jewellery before applying any of these and before activities involving water or chemicals. Store separately from harder minerals that could scratch the surface, and away from direct sunlight for extended periods. The perfect cleavage in one direction means sharp impacts can cause splitting. Handle with care and store in padded, individual compartments where possible. Traditional Associations While this guide focuses on the mineralogy and science of Turquoise, it carries one of the deepest and most geographically widespread cultural and spiritual histories of any mineral on Earth. Associated across many traditions with protection, communication, wisdom, and connection to the natural and spiritual world, it has been revered from ancient Egypt to the American Southwest for thousands of years. In chakra work it is connected to the Throat and Heart Chakras. These associations are rooted in deep cultural tradition rather than scientific properties. For a full exploration of how to work with Turquoise spiritually, see our dedicated guide: Turquoise: Harnessing the Power from Self-Expression to Serenity. Summary Turquoise is a hydrated copper aluminium phosphate mineral formed in arid environments where copper, aluminium, and phosphate combine under oxidising conditions. Its distinctive blue coloration is produced by copper, its green variations by iron substitution, and its extraordinary cultural significance by a combination of visual impact, relative scarcity, and the depth of its associations across civilisations from ancient Egypt to the modern American Southwest. Understanding the range of treatments in the commercial market is essential for any serious buyer, and the distinction between natural, stabilised, enhanced, and simulated material is worth knowing clearly. For those who engage with Turquoise at any level, from casual admirer to serious collector, it is a mineral whose story spans more of human history than almost any other. Browse our full Turquoise collection to find natural specimens, stabilised pieces, and jewellery grade material. 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 Azurite: The Mineral That Coloured Medieval Paintings Chrysocolla: Express Your Truth with Serenity Malachite: From Ancient Egyptian Cosmetics to the Winter Palace Lapis Lazuli: Speak Your Truth, Embrace Your Wisdom Carnelian: Unleash Your Inner Fire Chrysoprase: The Nickel-Coloured Chalcedony That Has Decorated Palaces and Cathedrals for Three Thousand Years A Beginner’s Guide to Mineral Chemical Properties and Classification A Beginner’s Guide to Mineral Physical Properties

on Mar 05 2025

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Amazonite: The Feldspar That Was Never From the Amazon

What Is Amazonite? Mineral Group: Potassium Feldspar | Category: Tectosilicate | Formula: KAlSi₃O₈ | Hardness: 6 to 6.5 (Mohs) Amazonite is a blue-green variety of Microcline, a Potassium Feldspar mineral composed primarily of potassium aluminium silicate. It belongs to the Tectosilicate group, the largest and most structurally complex division of the silicate minerals, in which silicon-oxygen tetrahedra are linked in a continuous three-dimensional framework rather than the chains or sheets seen in other silicate subgroups. This framework structure gives feldspar minerals their characteristic combination of moderate hardness, perfect cleavage, and relative chemical stability. Despite its name, Amazonite has never been reliably sourced from the Amazon River Basin. The name is believed to originate from early European explorers who mistakenly associated a green stone from the region with this mineral. The true source of that confusion remains unresolved, but the name has persisted in mineralogical literature regardless. Today, significant deposits are found in Brazil, Madagascar, the United States, Russia, and parts of Australia. Key Physical Properties at a Glance Property Detail Chemical Formula KAlSi₃O₈ Crystal System Triclinic Hardness 6 to 6.5 (Mohs) Specific Gravity 2.56 to 2.58 Refractive Index 1.522 to 1.530 Birefringence 0.008 Pleochroism Absent Lustre Vitreous to silky Fracture Uneven to splintery Cleavage Perfect in two directions Safe to Cleanse in Water Yes, briefly Amazonite's specific gravity of 2.56 to 2.58 is consistent with the feldspar family, lighter than most other silicate minerals of similar hardness. Its refractive index of 1.522 to 1.530 is modest, producing a vitreous to silky lustre, with the silky quality most pronounced where fine feldspar intergrowths create a subtle sheen across the surface. Birefringence is low at 0.008 and pleochroism is absent, consistent with its triclinic symmetry and the opacity of most commercial specimens. How Does It Form? Amazonite forms within granitic pegmatites, exceptionally coarse-grained igneous rocks that develop during the final stages of magma crystallisation. As a magma body cools, the most common minerals crystallise first, leaving behind a residual melt progressively enriched in water, silica, potassium, aluminium, and a range of trace elements. This volatile-rich residual melt has a much lower viscosity than the original magma, allowing ions to migrate freely and crystals to grow to considerable size over long periods of time. It is within these late-stage pegmatitic environments that Microcline Feldspar, including the Amazonite variety, develops its characteristic large, well-formed crystals. The slow crystallisation rate and chemically enriched environment are directly responsible for both the crystal size and the trace element content that contributes to Amazonite's distinctive colour. Amazonite commonly displays white streaks and veining produced by intergrowths of Albite, a sodium-rich feldspar, within the Microcline host. These intergrowths, known as perthitic texture, form during the slow cooling of the pegmatite as sodium and potassium feldspar phases separate within the same crystal. The resulting white patterning against the blue-green Amazonite background is entirely natural and is one of the mineral's most recognisable visual characteristics. The Colour of Amazonite: An Ongoing Scientific Question The cause of Amazonite's distinctive blue-green colour is one of the more genuinely interesting unsolved questions in feldspar mineralogy. Unlike many coloured minerals where the colouring agent is well established, the precise mechanism responsible for Amazonite's turquoise tones remains a subject of ongoing scientific discussion. Current research suggests that trace amounts of lead, rubidium, and thallium within the feldspar crystal structure play a role, likely in combination with structural defects or radiation-induced colour centres within the feldspar lattice. The presence of lead in particular has been investigated extensively, with some studies proposing that lead substituting for potassium within the crystal structure, in combination with water molecules or hydroxyl groups, produces the blue-green colour through a complex interaction with the surrounding atomic environment. What is clear is that not all Microcline Feldspar is Amazonite, and the specific combination of trace elements, structural conditions, and geological environment required to produce the colour is relatively uncommon. This selectivity is part of what makes Amazonite a distinct and valued variety within the broader feldspar family. It is also worth noting that because Amazonite may contain trace amounts of lead within its crystal structure, it should not be used in drinking water preparations or oils intended for prolonged skin contact. Amazonite Within the Feldspar Group Feldspar is the most abundant mineral group in the Earth's crust, accounting for approximately 60 percent of all crustal rock by volume. Amazonite sits within the Potassium Feldspar branch of this group alongside Orthoclase, Sanidine, and non-blue-green Microcline. Its closest visual relatives within the broader feldspar family include Labradorite, a calcium-sodium feldspar known for its iridescent schiller effect, and Sunstone, an oligoclase feldspar with metallic inclusions. The distinction between Amazonite and other blue-green minerals is worth understanding for collectors. Turquoise, which shares a similar colour range, is a copper phosphate mineral with a much lower hardness of 5 to 6 and a waxy rather than vitreous lustre. Chrysocolla, another visually similar blue-green mineral, is a copper silicate with a hardness as low as 2 to 4 and a distinctly different surface texture. Neither is a feldspar, and both have entirely different chemical origins. Amazonite's feldspar identity is most readily confirmed by its perfect cleavage, characteristic white perthitic veining, and vitreous lustre. Amazonite in History Amazonite has one of the longest documented histories of use of any mineral in this collection. Ancient Egyptian artisans carved it into amulets, decorative objects, and jewellery over 3,000 years ago, with notable examples recovered from the tomb of Tutankhamun. Its turquoise-green colour held significant symbolic value in Egyptian culture, associated with fertility, rebirth, and protection. Beyond Egypt, Amazonite has been found in pre-Columbian decorative objects in the Americas and has been used across cultures from ancient Mesopotamia to Imperial Russia, where it was incorporated into decorative stonework alongside other coloured minerals. Its long history of use across geographically separated cultures reflects both the wide distribution of its deposits and the consistent human attraction to its distinctive colour. Care and Handling With a hardness of 6 to 6.5, Amazonite is moderately durable but requires thoughtful handling due to its perfect cleavage in two directions. Perfect cleavage means the mineral will split cleanly along predictable planes if subjected to sharp impact, making it more vulnerable to chipping and fracturing than its hardness alone might suggest. Handle with care and avoid dropping specimens or subjecting them to sudden mechanical stress. Brief water cleansing is safe, but prolonged soaking is not recommended as sustained moisture can work into cleavage planes over time. Avoid strong chemical cleaning agents and ultrasonic cleaning, both of which can damage the surface finish and exploit natural cleavage weaknesses. Store Amazonite separately from harder minerals to prevent scratching, and away from softer minerals it might in turn scratch. As noted above, Amazonite should not be used in water preparations or oils intended for internal or prolonged topical use due to the potential presence of trace lead within its crystal structure. For a full guide to safe cleansing methods for all your crystals, see: How to Cleanse and Recharge Your Crystals. Traditional Associations While this guide focuses on the mineralogy of Amazonite, it is widely used in spiritual and wellbeing practices. It is traditionally associated with calmness, clarity, communication, and harmony, and is commonly linked to the Heart Chakra and Throat Chakra in crystal healing systems. These associations are rooted in cultural and traditional use rather than scientific properties. Shop Amazonite Explore our Amazonite collection for a beautiful variety of minerals and crystals. Summary Amazonite is a blue-green variety of Microcline Feldspar formed within the volatile-rich conditions of granitic pegmatites. Its colour, still not fully explained by science, is linked to trace elements including lead and structural defects within the feldspar lattice. Its white perthitic veining, perfect cleavage, and long human history make it one of the most mineralogically and culturally interesting feldspars available to collectors. For collectors, it offers a window into the complex late-stage chemistry of igneous systems and one of mineralogy's genuinely open colour questions. For general buyers, it is a striking, historically significant mineral whose turquoise tones have attracted human attention for over three thousand years. 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: Labradorite: Gateway to Intuition and Spiritual Insights Turquoise Mineral Guide Chrysocolla Mineral Guides Smokey Quartz Mineral Guide Agate: Mineral Profile, Formation, and Banding Explained Black Tourmaline: The Mineral That Generates Its Own Electricity Pyrite: The Mineral That Fooled the World and Still Fascinates It Rhodonite: The Pink Mineral With a Dark Secret

on Jan 19 2025

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