There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
tambin
noun. cauldron
tambina
adjective. of copper
A word appearing as ᴱQ. tambina “of copper” in the Qenya Lexicon of the 1910s, adjectival form of ᴱQ. tambe “copper, bronze” under the early root ᴱ√KALA “shine golden” (QL/44).
Neo-Quenya: Since I use ᴺQ. tambë only for “bronze” for purposes of Neo-Quenya, I would use ᴺQ. tambina as “of bronze” while for “of copper” I would use ᴺQ. urusta.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
A noun appearing as ᴱQ. tambin (tambind-) in the Qenya Lexicon of the 1910s somewhat cryptically glossed “a copper or cauldron”, derived from the early root ᴱ√TAMA “beat; smelt, forge” (QL/88). It also appeared in the Poetic and Mythological Words of Eldarissa of the same period, with the more straightforward gloss “cauldron” (PME/88).
Neo-Quenya: The root √TAM appeared in Tolkien’s later writing in connection to craft words, so I would retain this word as ᴺQ. tambin “cauldron” for purposes of Neo-Quenya.