where does graphite come from to make pencils
Graphite From the 16th century, all pencils were made with leads of English natural graphite, but modern pencil lead is most commonly a mix of powdered graphite and clay; it was invented by Nicolas-Jacques Conté in 1795.[39][40] It is chemically unrelated to the metal lead, whose ores had a similar appearance, hence the continuation of the name. Plumbago is another older term for natural graphite used for drawing, typically as a lump of the mineral without a wood casing. The term plumbago drawing is normally restricted to 17th and 18th century works, mostly portraits.
Curling The granite for the stones comes from two sources: Ailsa Craig, an island off the Ayrshire coast of Scotland, and the Trefor Granite Quarry in Wales.
Import quota Quotas, like other trade restrictions, are typically used to benefit the producers of a good in that economy.
In situ In chemistry, in situ typically means "in the reaction mixture."
Condensation polymer Polyester is created through ester linkages between monomers, which involve the functional groups carboxyl and hydroxyl (an organic acid and an alcohol monomer).
Nandalal Bose He was given the work of illustrating the constitution of India