I am trying to encrypt an SD card but there is no "encrypt" option
I'm trying to encrypt an sd card on my iMac 27 running the latest Majave. There is no option to "erase encrypted" in Disk Utility and no option to "encrypt" in Finder. I can decrypt in finder if a card is already encrypted - but not encrypt a new card. Cards are correctly formatted in mac OS extended journaled.
iMac, macOS 10.12