June 2018 - last edited June 2018
you can get rare crates on the truck, by completing later sectors, or from doing the daily bounties. Gems can be obtained in blue uncommon crates, linking your email, or can be given by devs when they have to change something that affects players and want to give compensation in some way, and presumably after the pre-alpha microtransactions but no MTs for now.
June 2018
Thanks.