One of our local volunteers has written an article to give you an introduction to Alum. Come and see some real alum at the museum - and a unique urine barrel... Alum was used as a mordant or fixative for dyes in the textile industry, for waterproofing leather, in the manufacture of parchment, glass and candles, and as a fire-retardant. As a fixative for natural dyes it was essential to allow the finery of the Church, the crown or the court to be distinctive from the drab colo

Look closely at a piece of jet and it doesn’t look particularly impressive at first. Fresh from the cliff, it is not the deep, glossy black that we associate with Victorian jewellery. It is often brownish-grey, dull, and easy to mistake for an ordinary lump of coal. But polish it, and something remarkable happens. The surface transforms into a deep, velvet black that catches the light like glass. For centuries, this strange little piece of fossilised woodland has been pulled