Garnet is a naturally occuring silicate mineral deposit in the form of rocks, alluvial or aeolian deposits, mine deposits (granulated), river (or lacustrine) and beach deposits. Most mineral sands deposits are found in unconsolidated fossil shorelines several hundreds of metres to tens or even hundreds of kilometres inland from the present coastline due to an accumulation process of sedimentation that progressively brought eroded minerals from ancient volcanoes to fill the exisxting shoreline and having it regress till its actual position. The harder species of garnet like almandine and pyrope are used for abrasive purposes while softer ones like spessartite, andradite are used in jewellry as semi precious stones. Garnet hardness varies from 6.5 to 8 on the Mohs scale, in nature while significant differencies can be found among alluvial and crushed specimens.
Alluvial garnet coming from beaches, river deposits or underground mines is usually coming together as aggregate with the so called mineral sands or rare earths as ilmenite, leucoxene, rutile, zircon and gold being garnet a relatively low priced media with comparison to the principal valuable heavy minerals including titanium minerals as ilmenite and rutile, and variations as pseudo rutile and anatase.