Rock Crystal Quartz W Mary Ann Cornwall Genuine Mineral Specimen with Certificate of Authenticity

Genuine Rock Crystal Quartz – W Mary Ann, Menheniot, Cornwall, UK

This Rock Crystal specimen from W Mary Ann, Menheniot, Cornwall, England, is a genuine and carefully selected example of Cornish quartz mineralisation. The photograph provided shows the exact specimen you will receive. Please refer to the images for full sizing details and accurate scale.

This crystal includes a Certificate of Authenticity lifetime guarantee generic card confirming its genuine origin and mineral identification.

Mineral & Geological Classification – Rock Crystal (Quartz)

Rock Crystal is the transparent, colourless variety of Quartz, composed of silicon dioxide with the chemical formula SiO₂. Quartz belongs to the silicate mineral group and crystallises in the trigonal division of the hexagonal crystal system.

Mineral Name: Quartz (Rock Crystal variety)
Chemical Formula: SiO₂
Mineral Group: Tectosilicate
Crystal System: Trigonal
Hardness: 7 on the Mohs scale
Lustre: Vitreous
Transparency: Transparent to translucent

Quartz is one of the most abundant minerals in the Earth’s crust. Rock Crystal specifically refers to the clear, well-formed crystals that develop in open cavities, fractures and hydrothermal veins.

Quartz crystals typically form six-sided prisms terminating in six-sided pyramids. Natural growth striations may be visible along prism faces, and internal inclusions may occur depending on formation conditions.

Geological Setting – W Mary Ann, Menheniot

W Mary Ann is part of Cornwall’s historic mining district, associated with the Cornubian granite batholith formed during the late Carboniferous to early Permian periods. The intrusion of granite generated hydrothermal systems that deposited a wide range of minerals within fractures and lodes cutting through surrounding rocks.

Rock Crystal from this locality formed through the precipitation of silica-rich hydrothermal fluids within open spaces in mineral veins. As these fluids cooled, quartz crystallised slowly, allowing well-defined crystal forms to develop.

Cornish hydrothermal systems are known for producing quartz associated with minerals such as cassiterite, tourmaline, fluorite, galena and arsenopyrite. Quartz often serves as the primary gangue mineral within these metalliferous veins.

Crystal Characteristics & Notable Traits

Rock Crystal from W Mary Ann may display:

• Well-formed hexagonal prism structure

• Sharp pyramidal terminations

• Transparent to slightly milky internal zones

• Natural growth lines and minor inclusions

Clarity can range from optically clear to lightly included, depending on microscopic mineral entrapment or growth interruptions during crystallisation. Inclusions, when present, provide insight into the hydrothermal environment in which the crystal formed.

The vitreous lustre and hardness of quartz make it durable and visually striking. Its resistance to weathering contributes to its preservation in mineral collections.

Geological Importance & Collectibility

Cornwall is internationally recognised for its rich mining heritage and diverse mineralogy. Quartz specimens from named Cornish mines such as W Mary Ann are valued for their documented locality and geological context.

Rock Crystal specimens represent classic hydrothermal mineral formation and are suitable for mineral cabinets, educational displays and collectors of British locality minerals.

Because this is a genuine natural specimen, each crystal displays unique structural characteristics shaped by its geological environment. The photograph shows the exact Rock Crystal specimen you will receive.

Authenticity & Presentation

This Rock Crystal Quartz specimen from W Mary Ann has been carefully chosen for crystal form, clarity and locality significance. Included with your purchase is a Certificate of Authenticity lifetime guarantee generic card confirming its genuine origin from Menheniot, Cornwall, England, UK.

Combining classic Cornish hydrothermal geology with the timeless clarity of Rock Crystal, this specimen offers mineral authenticity, documented provenance and collector appeal in one carefully selected piece.