Patterns of Gabbro - on aluminium?

I had a good conversation with Liza (artist - Printmaker/painter) today on the phone about etching with aluminium and copper sulphate and salt. I experimented with this briefly in 2004 with Friedhart Kiekeben and had good results. Liza reminded me that it bites quickly, creating deep lines in 10 minutes. The aluminium has plate tone, making aquatint less important. I could glue carborundum grit to the plate to create a denser, darker tone if wished. It's so much cheaper than using copper which I have been using with ferric chloride.

If possible, I'll try to obtain some copper sulphate before June and try a few small plates and then work with Liza, larger scale, in June.

I do like the textural patterns of Gabbro so may well use this as a starting point for work on aluminium.