How Do I Add A New Texture/Material to the Materials list on GMOD?

hi to whom may be reading

i made a thread yesterday asking if there is a earth/world material/texture for gmod…and one very helpful person gave me thelink to download the file

however…i cant get it to appear on the materials list

i copied and pasted the files (which are earth.vmt and earth.vtf) to C:\Users\paul\Desktop\New Folder\steamapps"mysteamname"\garrysmod\garrysmod\materials…but after trawling through the materials list…there was no “earth” material

have i done something wrong…or copy-pasted to the wrong file?

if anyone could help it would be most appreicated

thank you

“bump”

just to see if i get get some help…