The fining pot
mitsreph (mits-rafe')
a crucible -- fining pot.
is for silver
keceph (keh'-sef)
silver (from its pale color); by implication, money -- money, price, silver(-ling).
and the furnace
kuwr (koor)
a pot or furnace (as if excavated) -- furnace.
for gold
zahab (zaw-hawb')
gold, figuratively, something gold-colored (i.e. yellow), as oil, a clear sky -- gold(-en), fair weather.
but the LORD
Yhovah (yeh-ho-vaw')
(the) self-Existent or Eternal; Jehovah, Jewish national name of God -- Jehovah, the Lord.
trieth
bachan (baw-khan')
to test (especially metals); generally and figuratively, to investigate -- examine, prove, tempt, try (trial).
the hearts
libbah (lib-baw')
the heart -- heart.