I just need to know how you would write a particular harmonic on a stave for violin:

the harmonic, is where you are in 1st position, and then put your 3rd finger on the A string, (Where the D is), and this harmonic makes the A string sound 2 octaves higher.......

How would i write this......

I was thinking to put a normal notehead on open A string, and then one of those diamond note heads on the D above it....

Am i correct in saying that is the way it should be written?

You just put a diamond note on the D.

thanks