[meteorite-list] petrological type

[Francesco Moser]

Hello, I have a question about chondrites' petrological type number assigned
after the letters (like H, L, CM or CR ...).
I have just read something in internet but I think I have misunderstood
something.

Are the numbers from 1 to 7 in sequence or there are two different
sequences: 1 to 2 - 3 to 7 ??
1 to 2 is for the aqueous alteration degree in carbonaceous chodrites (1
high degree, 2 low degree)
3 to 7 is for thermal metamorphism  degree?


Thanks a lot

Ciao

<x>x<x>x<x>
Francesco