Pyrite and Sphalertite
Lucky Jim Mine
Zincton, British Columbia
Massive black sphalerite crystals with disseminated pyrite.
Sphalerite is the main ore mineral for zinc, and although relatively common, finding it in commercial amounts is somewhat rarer. The zinc will give the mineral a yellow or red hue, but iron can replace the zinc in the atomic structure, making the crystals black. Rarely, cobalt finds its way into the structure, and produces green crystals.
Pyrite is a common iron sulphide mineral found in many different geological settings. It has a brassy-yellow metallic colour that has caused many people to mistake it for gold, giving it its other name, “Fool’s gold”. Pyrite and gold can be quite easily distinguished from one another: pyrite is less yellow and much lighter and harder than gold, which can be scratched with a pocket knife. Pyrite often forms perfect cubes, which can grow to quite large sizes, because of its crystal structure. The word pyrite comes from the Greek word ‘pyr’ meaning fire, because it will spark if hit with other metal or stone objects.
Although sphalerite is a relatively soft mineral, it can be cut (faceted) into attractive gems that are used for mineral displays.
This particular specimen comes from the Lucky Jim mine in Zincton in West Kootenay region of southeastern BC. Today, Zincton is one of BC’s many ghost towns, slowly crumbling and rusting, overgrown by the surrounding forest. In its heyday, around 200 people lived there, working the rich Lucky Jim zinc claims in the surrounding area.
Zincton was founded in 1892 and at one point was the largest producer of zinc in the Slocan area. It was even served by the Kaslo and Slocan Railway line, which transported ore to the Pilot Bay smelter to the south. The town was destroyed by a fire in 1910 but was rebuilt in 1927 by the Victoria Syndicate, who had acquired several of the surrounding zinc claims.
In the late 1800s, many prospectors came to the Slocan area in search of silver. Many were disappointed to find zinc, even in such abundance as found on the Lucky Jim claims. However, the turn of the century brought new industrial processes and the demand for zinc soared.
The ore at the Lucky Jim mine is mainly sphalerite and pyrite with gangue (waste) minerals calcite and minor amounts of quartz. The ore occurs as pods or thin veins in limestone host rock. Several main ore zones were mined, each contained within fractured zones of rock that allowed the ore-bearing fluids to move through the host rock and ultimately form the deposits.
Production from the Lucky Jim mine at Zincton began with the first shipment of ore in 1893 and continued intermittently until 1959, when ore reserves were depleted. The total recorded production amounts to 1,065,798 tonnes with 18,634,368 grams silver, 2799 grams gold, 194,847 kilograms cadmium, 3,697,184 kilograms lead and 79,798,689 kilograms zinc.
Store: Association for Mineral Exploration (AME)
Accession #: AME 387
Primary Mineral: Sphalerite
Secondary Mineral: Pyrite
Site Locality: Lucky Jim Mine
Location: Zincton, British Columbia
Special Features: n/a