h₂ey-es-

“metal, bronze, copper ore”

Widely acceptedmaterialmetallurgy

ore, aes, era

Root yielding Latin aes (bronze/copper), English ore, era (from counting in bronze).‌‌‌‌‍‍‍‍‍‍‌‌‍‍‌‍‌‌‍‍‌‍‍‍‌‌‌‌‍‌‌‍

bʰerdʰ-“to cut, split, separate”bʰerǵ-s-“to protect by enclosing”bʰreg-mn̥“that which breaks, fragment”deru-“tree, wood, to be firm”dʰeyǵʰ-mn̥-₂“wall, thing built from clay”dʰrew-“to be firm, to be solid”dóru“tree, wood, oak”doru-mn̥-“beam, timber, spear-shaft”