Criticisms and Responses: Gold and other metals

There are various primary criticisms that tend to be hurled at the Book of Mormon, but which have been addressed many times. One need only use Google to dredge them up, but similarly, Google can be used to find the counter-arguments. More people ought to do the latter when they see the former. This series of posts represents my responses to those criticisms.  


Criticism: Pre-Columbian Americans didn't have or use gold or other precious metals.

Response: Simply untrue. Excavations at Zaculeu, and many other sites, have turned up metalwork. Also found at Zaculeu was tumbaga, which is a gold/copper alloy that, when worked into thin sheets, almost perfectly matches the description of the metal the gold plates were made of and is excellent for engraving and was, in fact, used extensively in pre-Columbian America for making religious objects meant to be preserved for ages.

Given that none of this knowledge was available to him at the time, is it just Joseph Smith's lucky guess that Moroni would use tumbaga-like metal plates, made of non-corrosive and microbe-resistant metal with a low melting point that is easily pounded and shaped into thin, foil-like leaves for engraving?