Can you identify this bevelled grey 2x1 piece? I found this incredible MOC of the Ghost In The Shell robot and found a piece I have never seen before.  Is it a LEGO piece and, if so, can you help me identify it?



Link to the image source: https://www.flickr.com/photos/coleblaq/31984689954/in/faves-43378406@N08/
It's 99563 LegoMinifig, Utensil Gold Ingot (Bar) in Light Bluish Grey.



Originally used for Gold pieces, nowadays regularly found as bricks and other wall decorations, for example on the ground floor of 10251 Brick Bank.