copper, tin
錫 centers on the metal tin, and by extension copper, as a metallic substance. The two meanings are linked as specific metals, with tin being the primary sense.
錫 combines the metal radical 金 with 易, which likely contributes the sound. The character originally referred to tin, a metal.
The left side 金 means metal, and the right side 易 looks like a container. Picture a metal container holding shiny tin or copper.
For セキ, imagine a tin cup making a sharp 'seki' sound when you tap it: seki -> セキ, the metal ringing out.
tin (Sn)
khakkhara (staff topped with metal rings traditionally carried by monks); pewter staff
tin chloride
preaching tour
detinning; removal of tin and copper
stannoidite
stannous oxide (SnO)
bishop's staff; khakkhara
tin pest
tin wedding (anniversary); 10th wedding anniversary
yellow bird's-nest (Monotropa hypopitys); pinesap; false beechdrops
cassiterite
tin foil; tinfoil
tinware
Burmannia championii (species of flowering plant)
stannite