Delivery to my PO Box ~12.19.2011 (Can't recall exact date, no markings on envelope)

Delivery contents:
Front of envelope/stamps
currency, front
currency, back
A blue rock/mineral
A blue rock/mineral, photo #2


The color looks perhaos a bit too bright, but if that's due to the flash, this might be blue 
Kimberlite (which certainly fits with South Africa and, apparently, Arizona).

CvK 07/28/2021
 Tanzanite, possibly, would be deeper blue.

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