Local Rock Dust
No matter what you call them, rock minerals are a cheap and effective way to remineralise your soil. They are often called crusher dust or cracker dust. In general, the cheapest place to purchase them is at landscape supply outlets. Many will sell by the shovel full for those without a trailer. Note that you will only be able to fit a maximum of 0.5 cubic metres on a trailer as the material is VERY heavy.
Igneous Metamorphic Rock
Basalt, Greenstone, or Hornfels rock dusts provide calcium, magnesium, and phosphorous. They also provide many other valuable trace elements such as iron and silicon.
The following Brisbane area quarries mine igneous metamorphic rock:
- Boral Petrie quarry (Greenstone)
- Boral Narangba quarry (Greenstone)
- Boral Purga quarry (Basalt)
- Boral Narangba quarry (Hornfels)
When sourcing rock dust from a landscape supply company, ensure that you ask which quarry the material came from. Even better, ask the quarry company for a recent mineral analysis.
Granite sourced from the Brisbane suburb "The Gap" contains high quality minerals, but most decomposed granite material will do.
When sourcing deco from a landscape supply company, ensure that you ask which quarry the material came from.