Bornite & Chalcopyrite | Hingston Down Quarry, Cornwall

A striking 485g Cornish mineral specimen featuring metallic bornite and chalcopyrite, displaying rich golden-brassy surfaces, coppery tones and beautiful areas of purple-pink iridescence. Originating from Hingston Down Quarry near Gunnislake, Cornwall, this specimen brings together dramatic natural colouration, complex sulphide mineralisation and the geological heritage of eastern Cornwall.

With its contrasting metallic colours, rugged formation and intricate surface textures, this specimen makes an unusual addition to a British mineral collection.

Specimen Description

This substantial specimen displays an irregular, naturally textured formation with extensive metallic mineralisation across its exposed surfaces.

The most immediately striking feature is the contrast between brilliant golden-brassy patches and darker charcoal-grey mineral surfaces. Scattered across these areas are flashes of copper-pink, violet and magenta iridescence, creating a beautiful multicoloured metallic appearance.

The golden areas are consistent with the appearance of chalcopyrite, while the coppery and purple-toned surfaces are characteristic of tarnished copper sulphide minerals, including bornite.

Unlike polished or artificially enhanced specimens, this piece retains its rugged natural character, with uneven mineral surfaces, small cavities, exposed edges and variations in metallic lustre.

Several areas exhibit granular and finely crystalline textures, while other sections appear more compact and massive. Small recesses and darker openings add depth to the formation.

The reverse and side surfaces reveal further golden mineralisation, rusty orange-brown alteration and darker metallic patches, making the specimen interesting to examine from multiple angles.

The natural iridescence is particularly attractive under directional lighting, with the metallic surfaces reflecting different colours depending on the viewing angle.

Weighing 485g, this is a substantial raw specimen with excellent visual appeal for collectors of Cornish minerals, metallic sulphides and unusual geological formations.

About the Minerals

Bornite (Cu₅FeS₄) is a copper iron sulphide mineral belonging to the orthorhombic crystal system, with a Mohs hardness of approximately 3.

Fresh bornite typically displays a copper-red to bronze-brown metallic appearance. When exposed to air and natural oxidation processes, its surface may develop distinctive iridescent colours, including purple, blue, pink and violet.

This colourful tarnishing has earned bornite the popular nickname Peacock Ore, although that commercial name is also frequently applied to artificially treated chalcopyrite.

Bornite commonly occurs in hydrothermal mineral deposits alongside other copper-bearing minerals, including chalcopyrite, chalcocite and various secondary copper minerals.

Chalcopyrite (CuFeS₂) is a copper iron sulphide mineral belonging to the tetragonal crystal system, with a Mohs hardness of approximately 3.5–4.

It is one of the most important copper ore minerals and is recognised by its characteristic brassy-yellow colour and metallic lustre.

Chalcopyrite forms in a wide range of geological environments, including hydrothermal veins, magmatic deposits and metamorphosed mineral systems.

Its surface may develop iridescent tarnishing through chemical alteration, sometimes producing colours similar to those associated with bornite.

Both bornite and chalcopyrite are recorded from Hingston Down Quarry, making this mineral association consistent with the documented mineralogy of the locality.

Quarry History & Cornish Heritage

Hingston Down Quarry is situated approximately 2km west of Gunnislake, within the parish of Calstock in eastern Cornwall.

The quarry works a relatively small granite intrusion forming part of the wider Cornubian granite system, a geological province responsible for much of Cornwall's celebrated metalliferous mineralisation.

The granite at Hingston Down is predominantly fine-grained biotite granite and forms part of a ridge between the larger granite masses of Bodmin Moor and Dartmoor.

Throughout the granite are numerous mineralised fractures, joints and veins, many of which follow an approximately east-west orientation.

These geological structures provided pathways for mineral-bearing hydrothermal fluids, allowing metallic sulphides and other minerals to crystallise within fractures and cavities.

The quarry has become an important mineralogical locality because its granite workings have exposed a diverse range of mineralised veins and associated secondary minerals.

Documented minerals include chalcopyrite, bornite, arsenopyrite, sphalerite, molybdenite, wolframite, scheelite, fluorite, quartz and numerous other species.

Hingston Down Quarry is particularly interesting because it exposes mineral associations associated with Cornwall's complex granite-related hydrothermal systems.

The site's mineralogy has attracted specialist study, including research into its ore-bearing veins and Alpine-type mineral cavities.

A detailed study by Weiss, Green, Hooper and Elton, published in the mineralogical journal Lapis in 2007, documented the diverse mineral occurrences of Hingston Down Quarry, including bornite and chalcopyrite.

The quarry is also recognised in the Geological Conservation Review of England and Wales, which describes its granite geology, mineralised veins and important mineral occurrences.

Nearby Hingston Down Consols forms part of the wider historic mining landscape. However, the historic mine workings and the modern aggregate quarry are distinct localities and should not be confused.

While much of Cornwall's mining heritage is associated with underground tin and copper extraction, Hingston Down Quarry demonstrates how later quarrying activity has also contributed to the discovery and documentation of important British mineral specimens.

Specimens attributed to Hingston Down Quarry offer collectors an opportunity to appreciate the complex geological processes that shaped Cornwall's mineral-rich landscape.

Intention & Associated Chakras

In traditional crystal healing practices, bornite and chalcopyrite are associated with complementary symbolic qualities:

• Bornite: Transformation, positivity, emotional balance and embracing change.
• Chalcopyrite: Confidence, creativity, personal growth and motivation.

Associated Chakras: Solar Plexus Chakra, Sacral Chakra and Crown Chakra.

Intention: Abundance and Spiritual Growth.

These associations belong to crystal healing traditions and are not scientifically established properties of the minerals.

Natural Formation & Symbolism

As a natural raw mineral specimen, this piece retains its irregular shape, exposed metallic surfaces and intricate mineral textures.

Bornite and chalcopyrite are formed through geological processes involving copper, iron and sulphur, often within mineral-rich hydrothermal environments.

The contrast between the golden metallic areas and purple-pink iridescence symbolically reflects transformation, change and the unexpected beauty of natural geological processes.

Raw mineral formations are traditionally associated with authenticity, connection to the natural world and appreciation of the Earth's geological history.

The colourful appearance of this specimen also makes it a particularly appealing piece for collectors who appreciate the natural diversity of metallic minerals.

Specimen Details

• Minerals: Bornite & Chalcopyrite
• Quarry: Hingston Down Quarry
• Locality: Gunnislake, Calstock, Cornwall, England
• Weight: 485g
• Measurements: 92.0mm × 66.0mm
• Formation: Natural raw metallic sulphide specimen
• Colour: Brassy gold, copper, charcoal grey, purple and pink iridescence
• Lustre: Metallic
• Condition: Natural uneven mineral surfaces, irregular edges, small cavities and areas of surface alteration
• Quantity: One individual specimen
• Price: £84.00

You will receive the exact specimen photographed. Natural mineral specimens may contain fractures, uneven surfaces, cavities, delicate mineral growth and variations resulting from their geological formation.

Care: Keep dry and avoid chemical cleaners, prolonged moisture exposure or abrasive polishing. Handle gently and wash hands after handling. Do not use for crystal-infused drinking water.

Sources & References

The following geological and mineralogical resources document Hingston Down Quarry and its recorded mineral occurrences:

1. Geological Conservation Review – Hingston Down Quarry and Hingston Down Consols. Geological assessment originally published by the Joint Nature Conservation Committee, documenting the granite intrusion, mineralised veins and significance of the locality.
2. Mindat – Hingston Down Quarry, Gunnislake, Cornwall. Mineral locality database recording bornite, chalcopyrite and numerous other minerals associated with the quarry.
3. Mindat – Bornite from Hingston Down Quarry. Specific occurrence record confirming bornite as a documented mineral from the locality.
4. Mindat – Chalcopyrite from Hingston Down Quarry. Specific occurrence record confirming chalcopyrite as a documented mineral from the locality.
5. Weiss, S., Green, D.H., Hooper, J.J. & Elton, N. (2007). Erzgänge und "Alpine" Klüfte: Die Mineralien des Hingston Quarry, Calstock, Cornwall. Lapis, 32(11), 13–25, 54. Specialist mineralogical study cited in the Hingston Down Quarry locality records.

Historical and geological references relate to the documented quarry locality. The provenance of this individual specimen is based on its supplied collection information. The mineral identification has not been independently laboratory verified. The presence of iridescent tarnishing alone does not conclusively distinguish bornite from altered chalcopyrite.