Aeneolithic
adjective
Ae·ne·o·lith·ic ā-ˌē-nē-ō-ˈli-thik 
: of or relating to a transitional period between the Neolithic and Bronze ages in which some copper was used
Word History
Etymology
Latin aēneus, aēnus "made of bronze (or another alloy of copper)" (from aer-, aes "bronze, brass, copper" + -nus, -n-eus, suffixes of materials) + -o- + -lithic — more at ore entry 1
First Known Use
1886, in the meaning defined above