If you ask me, sunstone (g4 r63 sunburst) should get the plain "sunstone" tag:
1. While it's rule 63, being g4 makes it more relevant to the site than the artifact (more uses)
2. It would benefit greater from the change (its tag is more cumbersome to type than the g1 artifact)
The g1 could be "sunstone artifact"? Unless you want to keep it the same.