From katham; properly, something carved out, i.e. Ore; hence, gold (pure as originally mined) -- ((most) fine, pure) gold(-en wedge).
see HEBREW katham
H3800. kethem
כֶּ֫תֶם noun masculineLamentations 4:1 gold, in poetry and late (perhaps loan-word in Hebrew; Phoenician has proper name, masculine כתם; Sabean כתם HalEt. Sab. 190; kaθam¹ as loan-word in Egyptian, Bondi80f.); — ׳כ absolute Job 28:19 3t., כָּ֑תֶם Proverbs 25:12; construct כֶּתֶם Isaiah 13:12 3t.; — ׳כ אוֺפִיר 13:12 gold of Ophir ("" מָּ֑ז), so Job 28:16; Psalm 45:10; ׳כ אוּפָ֑ז Daniel 10:5 (read perhaps אוֺפִיר for אוּפָז q. v.); ׳כ alone Job 31:24 ׅ "" ׳חֲלִיכֿ (זָהָב Proverbs 25:12 ornament of gold ׅ "" ׳כ מָּ֑ז (זָהָבנֶזֶם Song of Solomon 5:11; ׳כ טָהוֺר Job 28:19; ׳הַכּ הַטּוֺב Lamentations 4:1 "" זָהָב.
כתן (√ of following, = clothe? so ZehnpfBAS i, 532, who derives therefrom Assyrian kitinnê, linen, cloth, = Arabic see also Aramaic כִּיתָּנָא and below)