Quartz Crystal Sandwich – Victorian Goldfields: Specimen 18

Notable Features

This quartz crystal specimen weighs 164 g and measures approximately 9 × 8 × 4 cm (Width × Length × Height). It displays a High sulfide level, with quartz crystals growing in voids between two layers of bedrock, forming a striking “sandwich” structure.

Notable features include abundant pyrite, sharp quartz crystals in open spaces, and strong contrast between quartz and host rock.

Sulfide Level

High – The specimen is heavily mineralized, with abundant pyrite throughout the quartz and along crystal surfaces. Sulfides are easily visible to the naked eye.

See how we rate sulfide levels by visiting our FAQ section.

Mineral Assemblage

• Quartz – White crystals lining voids, growing into open spaces

• Pyrite – Abundant golden clusters and flecks throughout

• Chalcopyrite – Possible brassy inclusions among the pyrite

• Arsenopyrite – Fine metallic specks may be present

• Stibnite – [not evident]

• Tetrahedrite – [not evident]

• Iron oxides – Minor staining along bedrock surfaces

• Trace gold and silver (mostly refractory, with rare free gold possible)

Note: Not every specimen contains the full mineral assemblage above. Minerals may appear in varying amounts, and each specimen may only feature a subset. Each piece is unique and chosen for its visual appeal and geological character.

Geological Story

This specimen formed during the Silurian Period (~440–420 million years ago), when tectonic forces fractured submarine fan sediments in the Victorian Goldfields. Silica-rich hydrothermal fluids surged through these fractures and cooled slowly, crystallizing into quartz rather than the massive milky quartz common in Victoria.

Depending on conditions, the quartz developed as crystals lining open voids in a vein between two layers of bedrock — the “sandwich” structure — with sulfides such as pyrite, chalcopyrite, arsenopyrite, stibnite, and tetrahedrite deposited alongside. Over time, iron oxides added further color and contrast.

The Victorian Goldfields were historically mined for gold, silver, and antimony. While most of the precious metals are refractory and locked within sulfides, rare specimens containing visible free gold are known.

This specimen is not sold as “gold ore.” It is a collector’s specimen, chosen for its unique sandwich structure, sharp quartz crystals, and abundant pyrite, and for its geological significance as a fragment of one of Australia’s most famous gold regions.