From the geology course I took in 1975: Minerals are naturally occurring crystals of compound. Snow is a mineral, but volcanic glass is not. Rocks are amalgams of minerals and non-minerals.
In corpus linguistics, a collocation is a sequence of words or terms that co-occur more often than would be expected by chance. In phraseology, collocation is a sub-type of phraseme. An example of a phraseological collocation, as propounded by Michael Halliday, is the expression strong tea.
colloquium-an academic meeting or seminar usually led by a different lecturer and on a different topic at each meeting. conference-a prearranged meeting for consultation or exchange of information or discussion (especially one with a formal agenda).