The RM009 actually weighs less than 29 grams; the RM006 weighs 43 grams...
In terms of your question, you know, I have no idea on the weight for rose gold. Only to tell you that the case metal for a Richard Mille watch is substantial, so the weight will be somewhere around a Panerai case in the same metal. Just guessing here, and perhaps some other owners of RM005's and RM010's could chime in.
Andrew H
