Determining the authenticity of purported pre-Columbian artifacts is

Hey All,

Lots of discussion on this one. Let's see what I can do...

Determining the authenticity of purported pre-Columbian artifacts is never easy. Carbon-14 dating of these artifacts is often impossible due to contamination by radioactive palladium (which occurs naturally in the soils of Central and South America). However, historians and anthropologists have evolved two reliable criteria, which, utilized in combination, have proven effective for dating these artifacts. First, because authentic pre-Columbian artifacts characteristically occur in a coarse, granular matrix that is shifted by major earthquakes, they often exhibit the unique scratch patterns known as gridding. In addition, true pre-Columbian artifacts show a darkening in surface color that is caused by centuries of exposure to the minute amounts of magnesium in the soil of the Americas.

The criteria above would be LEAST useful in judging the authenticity of which of the following?

Breakdown. We have two methods: Check earthquake-related gridding and check for magnesium darkening. Where will these fail?

(A) An ax head of black obsidian, unearthed from a kitchen midden
PROBLEM: Darkening wouldn't work here (because it's black), but gridding would still work (obsidian is just glassy rock).

(B) A pottery bowl with a red ocher design, found in the ruins of a temple
PROBLEM: Both gridding and darkening would work here.

(C) A set of gold ear weights, ornamented with jasper pendants
PROBLEM: Both gridding and darkening would work here.

(D) A black feather cape from a king’s burial vault
ANSWER: It's black, so you can't check darkening, and it's made of feathers, so there won't be any gridding on the surface.

(E) A multicolored woven sash found near the gravesite of a slave
ANSWER: Gridding wouldn't work here (fabric), but darkening still would.

The answer is definitely D. Fun!

-tommy