lue

To lue is to separate fine particles from coarse material by shaking ore or crushed rock through a sieve, a primary step in tin and silver mining. The verb describes the physical action of agitation that causes lighter material to fall through mesh while heavier fragments remain on top. This process concentrates ore by removing waste and sorting material by grain size before further processing.

The practice is ancient in Cornish and Devon tin mining, where luing remained standard practice into the twentieth century. A worker called a luer would stand at a tilted sieve frame, shaking it rhythmically to encourage material downward. The sieve itself, made from horsehair, wire mesh, or silk stretched across a wooden frame, defined the size fraction being separated. Different mesh sizes were used in sequence to produce grades of ore suitable for different stages of smelting.

Luing appeared in written records of mining accounts and technical descriptions, though the term remained more common in speech than in formal documentation. Related work included ridding, which used a similar technique with a riddle sieve, and jigging, which used water and gravity rather than manual shaking. The terminology varied by region and mine, with some operations using lue interchangeably with riddle or sieve.

The work was often assigned to women and children, who could manage the lighter sieves and repetitive motion required. Luing was laborious but required judgment: too vigorous shaking damaged the ore by crushing valuable particles, while too gentle shaking left fine material unprocessed. The skill lay in finding the rhythm that separated effectively without loss.

Modern concentration equipment, including vibrating screens and jigs, replaced manual luing in most operations by the mid-twentieth century. The term itself has faded from active use in English mining, surviving mainly in historical records and regional dialect, though the process it describes remains fundamental to ore preparation across the industry.