it's been in the game since... well forever.
while I don't have my magic 2e book in front of me, I DO have have Magic in the Shadows, 3e magic source book.
Page 43
MATERIAL BASIS
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Any inanimate object can serve as a telsma (the base form of a focus), A wooden wand, a jeweled charm, a weapon, a car, an oddly shaped stone and so on. Because the Telesma's Object Resistance modifies the target number for enchanting tests, the more natural an object..... (see Object resistance table 182 SR3)
There we see a little table on the bottom of the page..
Natural Objects (tress, Soil, unprocessed Water) 3
Manufactured Low-tech Ojects and mats (brick, leater, simple plastics) 5
Manufactured High-Tech Objects and Mats (Advanced plastics, alloys, electronic Equipment) 8
Highly Processed Objects (Computers, Complex Toxic Wastes) 10+