About 90% of the world's extractable material, used for the manufacture of ornamental objects and jewellery, is in the Kaliningrad Oblast of Russia on the Baltic Sea. What type of material is this?
Which unstable, combustible material is used in the production of explosives, matches and electric batteries, as well as in etching copper, in manufacturing coloured glass, in the leather industry, in dyeing, and as an antiseptic?
