$90 for 5 lb of grit.

[Brooks_]

Avoid granite due to the chances of having heavy metals in the gravel

Pretty sure the grit I buy is granite.

 

[JacinLarkwell]

Pretty sure the grit I buy is granite.

It usually is

 

[Al Gerhart]

See if you can identify the type of granite with a picture of it and some geology pics online then you will find a rough description of the minerals composing the granite and a breakdown of the actual elements. Not all metals are bad, many like Iron are needed, just watch for the heavy metals like lead, trace uranium and the decay products of the uranium which are always present in nature.

 

[sdm111]

Thanks for the replies. I'll see what's available at the hardware store. I did grab some stones from the river. Everything here is similar to slate by the looks of it.

I feed mine lay pellets and have not given a grit in decades