From pencils to programming and graphene: Graphite’s role in the transmission of knowledge

Adam Blaxhall (UK) Once a mystery substance thought to be a type of lead, graphite is now one of the most vital components in the ever-expanding world of complex electronics. But this ‘mineral of extremes’ is more than just the familiar grey material we find in pencils. Rather, it is a specific form of the element, carbon (another is diamond) and, from writing products to electrical circuitry, graphite plays an increasingly important role in how we process, communicate and transfer information – and there’s still much to learn from its untapped potential. Graphite: the only mineral for the job A popular misconception is that lead pencils are made from lead (Fig. 1). Fig. 1. Putting lead in your pencil? Graphite was originally considered to be a form of lead and went by the name ‘plumbago’. In fact, they never have been. Graphite – mistaken for a form of lead – has been the main ingredient in the pencil since the largest, purest deposit of the mineral ever discovered was unearthed in Borrowdale in Cumbria, UK in the 1500s (Fig. 2). Fig. 2. Graphite. Graphite is ideal for pencils because its giant structure of carbon atoms – formed of honeycomb-like layers stacked on top of each other – is such that the bonds between atoms are stronger than the bonds between layers. It’s this physical property that gives graphite its soft and slippy texture, and allows the layers to slide off one another. So, when a pencil moves across a surface, … Read More

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Mining in ancient Greece and Rome

Dr Robert Sturm (Austria) Ancient civilizations had a high demand for raw materials, like clay, diverse rocks and, most of all, metals. These were required for buildings, crafts, agriculture, their armed forces, financial concerns, art and culture. Clays and rocks produced by opencast mining primarily served for the production of bricks and building blocks, which were used for civil and hydraulic engineering. They were additionally extracted for the manufacture of durable goods and art objects, such as dishes and statues. Metals – like gold, silver, copper, tin, iron and lead – being essential raw materials in antique civilisations, were commonly produced by underground mining. Gold and silver were mostly used as raw material for ancient coins. The use of noble metals in monetary economy has been going on since the seventh century BC, when barter trade was successively replaced by a monetary economy. Copper, tin and iron was mostly produced for the manufacture of arms, whereas lead was, among other things, used for the production of water conduits and as a stain for ornamental painting. Fig. 1. Some examples for the use of metals: lead was, among other things, used as stain for ornamental painting (left), whereas silver was used for coins (right). Ancient techniques used for the mining of raw materials Sufficient supplies of metallic and mineral raw materials required systematic mining, since only gold was found in large enough amounts in washes of brooks and rivers to make panning worthwhile. Other metals usually occurred as chemical components of … Read More

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