Garnet is a hard silicate mineral quarried in Australia, India, USA and South Africa.
As an expendable abrasive, it is more expensive than some other materials, but its high cleaning efficiency means less abrasive needs to be used. Hence, not only the cost of abrasive per square metre but also disposal costs can be reduced. Consequently, any cost comparisons with other abrasives should be done on the basis of cost per square metre.
Garnet can also be used as a recyclable abrasive, and as such, it has found use as a less expensive alternative to aluminium oxide.
Similar to Olivine, Garnet is used on both ferrous and non ferrous metal substrates. Its low dust quality is an attractive feature in environmentally sensitive areas. It also has excellent cutting properties, which make it good for water jet cutting.
Garnet has the highest specific gravity of all the natural and synthetic abrasives commonly used on site. This explains a lot of its popularity because, as noted, high specific gravity is a benefit for blasting efficiency. In addition, garnet has a high bulk density, which means it has more weight per cubic metre than other abrasives. The benefit of high bulk density, is that more can be stored in less space.
In its natural state, garnet has relatively high content of soluble salt. Nowadays, however garnet that has been properly washed and processed by reputable suppliers has soluble salt concentrations within or slightly above the guidelines set by ISO 11126.