What determines shape of dust nucleus?

[Nordstrom]

Is a dust nucleus, dust attached to air?
If water vapor molecules, attach themselves to dust nucleus in building visible [to the eye] snowflake, I'm supposing flake takes on shape of the dust. Does this mean "air" is shaped too?

Don't laugh; I'm most confused!

 

[Gear300]

I laughed.

 

[Nordstrom]

Yes, thank you for sharing Gear300,
but might I beg you to elaborate?
I really do want to understand this!

 

[Gear300]

I actually don't know either. I just posted that because of your last line.

Though, when you say air is shaped, what exactly do you mean?