1) Jet is a hard black mineral, found on Yorkshire’s east coast and much used formerly for making jewellery and buttons, especially rosary beads.
1351 et unum ciphum calcidoniae cum uno coopertorio de gete, Spofforth
1404 unum superaltare de blakegete , York
1408 j pare gete bedes gaudez dargent , Plumpton
1433 unum par precularium de geet , York
1498 a paire of geyet bedes , Wakefield
1559 one paire of geate beads with lyttil beads of currell xvjd, Gatherley
1618 my jerkin with jete buttons , Abbotside. From the early seventeenth century there is evidence that it was being mined and worked in and around Whitby: 1616 Richard Tipladie, jeat worker, East Row
William Cook, jeat-worker , Whitby. It should be noted that ‘jet-worker’ interchanged with ‘jetter’: 1614 Francis Trewett, jeater, Skinningrove in Brotton
1616 Francis Trewhitt, jeat worker , Brotton. This suggests that ‘jetter’ which occurred earlier as both a by-name and occupation may have had that sense. References have been noted three major locations in the fourteenth century: 1301 Gilbert Getour , Guisborough
1321-24 William le Getour , Hull
1377 John Coke, getour
William Jetour, Hull
1386 John Getour
1404 Thomas Bysshop, getour , York. Although it has to be considered a possibility that ‘getour’ could in some cases be used in the sense of ‘braggart’, a meaning given in the OED, the coastal locations of such occupational names is evidence that these were men who procured and/or worked jet, possibly by mining or from pieces cast up on the shore.