Amber ? Strange Glow

[deadwaterdevourer]

Hi all! First post here, spent some time reading the tips and rules so I hope I got everything right, but if I didn't please let me know.

 

I just got this specimen from a seller in Indonesia, who claimed it was Sumatran blue amber. The 'blue' part is skeptical, though it does seem to fluoresce a bit in direct sunlight.

 

I've run all the amber tests I am capable of doing (the rub-and-smell test, the static test, scratch test, black light test, acetone test) and for all intents and purposes it does seem to be amber, but I noticed last night when I was playing around with the black light, the amber retains a very faint residual glow after the black light is turned off, and the glow fades rapidly. I can't seem to find any resources online about whether this is normal or not, so I figured I should ask here.

 

The pictures below are three of the amber piece in standard room lighting, one of the residual glow, and one of the UV fluorescence (I removed it from the scale paper as the white was washing out the blue fluorescence on-camera).

[daves64]

The blue fluorescence does indicate that it is actual blue Indonesian amber. As for the lasting glow, some fluorescent mineral retain the glow for a short time, so it's no real surprise that amber might do the same. Although it could be a rare occurrence. Nice big chunk of amber either way. If you look closely at the tan areas, you may see hundreds or thousands of tiny air bubbles making it look almost foamy. 

[deadwaterdevourer]

Thanks daves! The residual glow threw me for a loop, so I'm glad to hear it's not an abnormal occurrence. Thanks!