Figure 1. The color changes of copper changes as it is chemically weathered at Earth's surface. Used with permission of the Copper Development Association Inc. www.copper.org.
Originally uploaded in NAGT:Publications:In the Trenches:2019 - Volume 9:In The Trenches - April 2019.
Image 202186 is a 5758 by 4600 pixel JPEG
Uploaded: Aug29 19