malta noun "gold", also name of tengwa #18 (Appendix E). The Etymologies (entry SMAL) instead has malda, q.v. for discussion, but according to VT46:14, the form malta originally appeared in the Etymologies as well. Also compare the root MALAT listed in PM:366.
Quenya
malta
noun. gold (metal), gold as material
malta
gold
culo
gold
[culo, culu ("k")noun "gold" (substance)] (KUL, VT49:47; the word culu_ also occurred in early "Qenya" [LT1:258], but in the Etymologies it was struck out; the regular Quenya word for "gold" is apparently _malta. In another version, culo meant "flame" [VT45:24], but this is apparently also a word Tolkien abandoned.)
Tar-culu
gold
Tar-culu ("k"), name listed in the Etymologies but not elsewhere attested. The second element is apparently culu "gold" (a word Tolkien seems to have abandoned); Hostetter and Wynne suggest that this may be an alternative name of Tar-Calion (= Ar-Pharazôn "the Golden"); see VT45:24.
laurë
gold
†laurë noun "gold", but of golden light and colour, not of the metal: "golden light" (according to PE17:61 a poetic word). Nai laurë lantuva parmastanna lúmissen tengwiesto "may (a) golden light fall on your book at the times of your reading" (VT49:47). In Etym defined as "light of the golden Tree Laurelin, gold", not properly used of the metal gold (LÁWAR/GLÁWAR, GLAW(-R), VT27:20, 27, PE17:159). In early "Qenya", however, laurë was defined as "(the mystic name of) gold" (LT1:255, 258) or simply "gold" (LT1:248, 268). In Laurelin and Laurefindil, q.v., Laurenandë "Gold-valley" = Lórien (the land, not the Vala) (UT:253) and laurinquë name of a tree, possibly *"Gold-full one" (UT:168). Laurendon "like gold" or "in gold fashion" (but after citing this form, Tolkien decided to abandon the similative ending -ndon, PE17:58).
A noun for “gold” appearing in Appendix F of The Lord of the Rings, also used as the name of tengwa #18 [t] (LotR/1123). In private notes on The Lord of the Rings, Tolkien specified that it was “gold metal” or “gold as material”, as opposed to laurë which was golden light or gold as a color (PE17/50-51, 159).
Conceptual Development: In Tolkien’s writings in the 1910s he had ᴱQ. laure as the mystical or magical name of gold as opposed to ordinary “gold” which was ᴱQ. kulu (LT1/100). The word ᴹQ. kulu “gold” survived until The Etymologies of the 1930s, but there its root ᴹ√KUL was redefined to refer to the color “golden-red” (Ety/KUL). Tolkien introduced a new word {malta >>} ᴹQ. malda for “gold (as metal)” derived from the root ᴹ√SMAL “yellow” (Ety/SMAL; EtyAC/SMAL). In notes on The Feanorian Alphabet from the 1940s Tolkien had the form ᴹQ. malta “gold” (PE22/50), and he seems to have kept that form thereafter. At some point he revised the root to √MALAT “gold” as well (PM/366).