Short answer, no, 3D Printed nylon is not microwave safe.

We were testing the water fastness of our dying process, the usual office experiments of soaking it in a glass of hot water for a couple of days (looking good) and then we wanted to dry it quickly, but maybe we dried it a little too quickly.  

As per the WSF material page the 3D printed nylon is dishwasher safe and heat resistant to 80c / 176f degrees, clearly the microwave was a little hotter....

Sorry for melting your Rodin Pendant Nat, I will print you another one..