Astrologers originally attributed gems to bring wellness and good fortune each month of the year. Thus, the stunning array of hues from the magical jewels in Birthstone Thinking Putty® is believed to bring focus, peace, and positivity! Thinking Putty® is non-toxic, won't dry out, and won't leave a sticky or slippery residue on your fingers, so it's great for stretching, molding, bouncing, tearing, popping, and playing by kids and adults alike.