What does the term 'Krishna-ayas' mean?

It means 'black metal', the term used in later Vedic texts to describe iron.

Ancient Technological History

UPSC Archival Analysis

The earliest literary references to iron in the Indian subcontinent are found in the Yajurveda, where it is referred to as 'Krishna-ayas'.

Exam Year

2016

Evidence Source

ID: ANC_LIT_2016_158 Ref: A History of Ancient and Early Medieval India by Upinder Singh