My roommate gets small hard green things stuck on her tonsils every few days. she says they do not hurt and is unsure if they smell.what are they?

Tonsils stones: Tonsil stones are irritating and cause local inflammation and pain to the affected tonsils. They typically are white concretions of calcium and bacteria but can be colored. Typically a conservative treatment of salt water gargles, waterpik to the affected area can dramatically improve the situation. For those who tonsil stones are unrelenting, removal of the tonsils is a curative but last resort.