Emerald some Questions

Hi
Who can me help with some questions

1. What mineral group does emerald belong to?
- Chemical group and if a silicate which silicate group (tetrahedra
group)?
2. What kind of rock would you look for to find the mineral?
- Rock group and rock type within group
3. What are three distinctive physical property(ies) of emerald?

I have some answer but i dont know if the are correct!

Thanks

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