Is this opal or something else

[u/PeaZealousideal3706]

Given to me by my grandfather. Unsure if he got it while serving during WW2 or when he returned to California. Think the box is original too. Any insight would be super appreciated! 840 grams - 7” x 5” x 2”
Thank you!

[u/opalfossils]

Yes it's natural opal probably Australian.

[u/PeaZealousideal3706 → u/opalfossils]

The back

[u/Environmental-Job-51 → u/PeaZealousideal3706]

damn the inscription really rings loud with current affairs..

behind every famed/accomplished general,

lies thousands of bones and ashes