These are fragments from a Mars meteorite. The cases are 2.25" long, 1.5" wide, and 0.5" thick. They weigh approximately 7 grams.
It is accompanied with a card that reads:
MARS ROCK
A piece of the Mars Meteorite
NWA 4925
(Olivine-Phyric Shergottite)
Product of Mars, Discovered in Morocco, Packaged in the USA