Mineral ores

19th century mineral exploitation in Fair IsleZoomShetland’s metal ores have been exploited for the last 2500 years, with excavations frequently turning up evidence of metal working. Throughout the Bronze and Iron Ages and into the Viking era peat bogs were a source of impure iron deposits or ‘bog iron’ which formed when iron salts dissolved in groundwater reacted with air.  Bog iron was smelted to produce tools and weapons. 

However, the main period of metal-ore mineral exploitation was the 19th Century when copper, lead, zinc, chromium, magnetite were all extracted.  Copper and iron mines were worked in southern parts of Shetland between about 1790 and 1920, most notable being the Sand Lodge mine in Sandwick, although 15 tonnes of copper ore was also removed from Copper Geo on Fair isle. 

About 10000 tonnes of magnetite was mined near Sullom Voe between 1954 and 1957 with an estimated 20000 tonnes still remaining. Still further north chromite deposits were extracted from opencast quarries on the island of Unst – some 50000 tonnes between 1820 and 1944. Semi-precious stones such as garnets can be found within Shetland’s metamorphic rocks, while traces of gold and platinum are known to occur in the North Isles.