Yury, yes ich can be transmitted during its tomont stage via rock, sand, inverts, coral, ect. This stage of the ich lifecycle can last up to 28 days and is unseen to the eye!
A lot of people forget this and don't realize there is a risk of transmitting ich when trading or purchasing a coral out of a system with fish.
Since the tomont stage lasts up to 28 days, the qt process and ich treatments (hypo / copper) should last a minimum of 4 weeks after the last spot is seen.
For comparison, the trophont stage (white spots on fish) only lasts 3-7 days.
~Eric