Granite dust

Would it be ok to use granite dust as a type of rock dust to amend my soil?

Absolutely.  It really is a type of rock dust and in my area granite is a common ammendment.   We're on limestone based soils here, so while I don't know exactly what minerals it brings,  I trust it adds some valuable variation.   With that in mind, I don't know if it would be as helpful in other soil types.

I have to agree strongly with Casie on using granite dust to amend limestone base soils, even sandstone base soils benefit greatly.
Granite rock dust is a great amendment for soils that lean to the basic side of the pH scale, granite base soils lean towards the acidic side so they are very useful in pH balancing.

Most Granites will contain in the vicinity of 50-60 minerals, most will be compound minerals with some crystallization of items such as silica.

Thank you both for sharing that information with me

What is the source? Around here we have decomposed granite. Its like a crumbly sand and is used for ammending.  With dust i think of byproduct from slab shops. Some slabs have fiberglass/resin backing. Some slabs are resin core(silestone,  etc). The dust cant be separated between slabs that have it or dont have it.

wayne fajkus wrote:Some slabs have fiberglass/resin backing. Some slabs are resin core(silestone,  etc). The dust cant be separated between slabs that have it or dont have it.

That very thing kept me from getting "rock dust" from a local company here that makes counter tops.  They have really beautiful pieces of rock they cut, and I thought that would be a great place to get rock dust until I saw just what you are talking about.  Now I'm looking for a source again.

wayne fajkus wrote:What is the source? Around here we have decomposed granite. Its like a crumbly sand and is used for ammending.  With dust i think of byproduct from slab shops. Some slabs have fiberglass/resin backing. Some slabs are resin core(silestone,  etc). The dust cant be separated between slabs that have it or dont have it.

Good point

If you are trying to source rock dust, look for shops that buy the quarry blocks and cut their own slabs, those will not have anything but pure rock dusts as a result of their cutting operation.

Where I am we have one shop that does counters that buys quarry blocks and cuts their own slabs as needed, we also have two "monument" companies that buy their granites in quarry blocks and do all their own cutting and polishing.
I have gotten dusts from both of these companies for free, all I have to do is bring containers and my scoop and broom. They get free cleanup work, I get free rock dust.
By the way, quarry blocks are usually measured in tons (I got to see a brand new deep red granite come in and it weighed 40 tons.)

Tip: lf the shop only has precut slabs, they will have some type of "backer" attached to prevent fractures during shipping to the shop.