/usr/share/gwyddion/glmaterials/Gold is in gwyddion-common 2.47-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 | Gwyddion resource GwyGLMaterial
0.24725 0.1995 0.0745 1.0
0.75164 0.60648 0.22648 1.0
0.628281 0.555802 0.366065 1.0
0.0 0.0 0.0 1.0
0.4
|