Virginia, the story at the website to which you referred is a nice
one, but in my opinion, Malachi 3:3 is not a good "source" for that
particular interpretation. As for the reality of how silver is
refined, I'll leave that to those who have actually done refining.
As for the text itself, the New Jerusalem Bible translates Malachi
3:2b-3 as follows: (referring to the coming of the Day of the Lord)
"Who can stand firm when he appears? He is like a refiner's fire,
like fuller's soap; he will take his seat, refining and purifying; he
will purify the Levites and cleanse them like gold and silver, and so
they shall be fit to bring offerings to the Lord." The image is to
burning out dross and impurities, not to God seeing God's image in
the molten silver.
The Hebrew verb, tsaraph, "to refine, test, purify," used here
twice, appears otherwise in various forms (including participles) in
Judges 7:4, 17:4
Isaiah 1:25, 40:19, 41:7, 46:6, 48:10
Jeremiah 6:29, 9:6, 10:9,14, 51:17
Psalms 17:3, 26:2, 66:10, 105:19
Nehemiah 3:8, 32
I mention these only to note the various contexts in which the verb
is used. I suspect it is also used in the Apocrypha, but I don't
have that concordance at hand.
Probably more than you wanted to know....