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A grey-silver ‘gunmetal’ coloured metallic ore.
Uses and History
Hematite is one of the oldest known minerals, having been originally named in around 300BCE by the Ancient Greeks. It was then renamed to ‘haematites’ by Pliny the Elder in 79CE, meaning ‘blood like’. The modern form was then simplified to ‘hematite’.
Hematite has a storied history and has been used for many different purposes. The most important use is, of course, as an ore of Iron!
It has been used to make a reddy-brown pigment since antiquity, both as part of red Ochre and red Chalk. It has also been used for jewellery making – particularly Victorian era intaglio carvings and mourning jewellery. However, most modern Hematite used in jewellery is synthetic.
It is extremely difficult to list the locales for Hematite, as it is one of the most common minerals on Earth.
Significant deposits are found in Australian, North America, Guinea, Brazil, Republic of the Congo, South Africa, and Venezuela.
Hematite can vary quite wildly in colour, depending on the form it takes.
Hematite is often a gunmetal grey to black, but fine grained specimens can be an earthy, clay like red colour. Some can even display rainbow colours.
Kidney Ore is a colloquial name given to botryoidal Hematite, as sometimes it has a similar appearance to a Kidney.
Rainbow Hematite can be a little confusing. There are two types – one synthetic, one natural. The natural mineral is referred to as Turgite – the synthetic is always referred to as rainbow Hematite.
The synthetic material is almost certainly another form of ‘Hemalyke’.
Specularite is a variant with tabular crystals, or sparkling flakes of Hematite.
There is a synthetic, man made material sold as Hematite, Hemalyke, or Hematine. This is often used for jewellery making, or tumbled – it is often sold in gift shops. It can be given a rainbow coating, too, and can look similar to heat treated Titanium.
This material is simply a synthetic form of ferrite magnet, usually with quite strong magnetism. This material should streak test with a dark brown or grey colour.
Magnetism: Most people would immediately jump to using a magnet to test an item being made of Iron – but Hematite is not always magnetic, and is not often highly magnetic. A synthetic form of Hematite does exist, and this is strongly magnetic. This synthetic material is referred to as Hemalyke or Hematine.
Hardness Testing: The Mohs hardness test is a tricky test for certain Hematite specimens – especially Specular pieces, as they can be prone to crumbling.
Streak Test: The ideal diagnostic test for Hematite is a streak test. Genuine Hematite will streak red to reddish brown.
Photos of Hematite
Two pieces of Hematite rubbed on a streak plate.
The earthy red specimen yields a more obvious colour,
the specularite piece has less obvious colour due to the
many small fragments which have broken off.
Hazards and Warnings
Excess consumption of Iron can cause quite a lot of organ problems. This is often more likely to be associated with soluble Iron salts, such as Iron tablets, but it could easily be linked to mining, arc welding, metalworking, and polishing with red rouge without proper ventilation. Repeated exposures can cause metal fume fever or siderosis.
Almost all rocks, minerals (and, frankly, almost all other substances on earth) can produce toxic dust when cutting, which can cause serious respiratory conditions including silicosis.
When cutting or polishing rocks, minerals, shells, etc, all work should be done wet to minimise the dust, and a suitable respirator or extraction system should be used.
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