According to the "Stones people magazine n°12" the Stones tongue come from Kali , the hindu female godess :
"The actual idea of using the Kali tongue as raw model for the logo, however, came from no body else but Mick Jagger! He discussed the concept with an art director, named JOHN PASCHE, who did the final design"
There's a longue article about this in this n°12,
Forum:
Tell Me