Finding every artifact in Stardew Valley to display in the museum can get tedious very quickly if luck isn't on your side. Artifacts can be dug up from the appropriately named Artifact Spots or from breaking geodes. Gems are easier to get thanks to ore deposits in the mines, but those such as the Dwarf Gadget are not as simple. If you want to craft, obtain the Rusty Key to Pelican Town's sewers, and get the Stardrop from the museum, then you'll have to pick up a Dwarf Gadget at some point in your Stardew Valley playthrough.