Robin Thicke re-upped his chakra security after visiting a gem store this week, by picking up a jumbo-sized crystal used for protection. The singer dropped by Crystalarium in West Hollywood on Tuesday, with 4-year-old son Julian in tow, and snagged a 2 foot high chunk of amethyst. Sources say Thicke spent a few thousand dollars on the stone — which is used for purification and protection, as well as getting in touch with one’s higher consciousness. Thicke has been making a full-court press to get back with wife Paula Patton, so…rock on, dude.