Grit Description

Aluminum Oxide Polish micron fine

The grit kit includes Silicon Carbide

Aluminum Oxide Polish, pictured above.


The predominant components of abrasives used in tumbling are made up of the chemicals Silicon Carbide and Aluminum Oxide. These two materials are presented in forms that vary in size or granularity.

Lapidary supplies are generally in the finer stage except for very rough tumbling processes.

The multiple sizes of the grit and polish are introduced at stages where the rocks and stones need more or less precision abrasion. The idea is to taper the size of the grit until it matches the size of the pits in the rocks. And then eventually the polish is as smooth or burnishes as opposed to removing elements of rock. So there is grinding and polishing. The grinding of course comes first. Then, when the rocks are shaped properly, you polish them to their most glossy.

Why Silicon Carbide

Silicon Carbide is chosen because it is a very hard material with lots of jaggedness. Unlike some other materials that are jagged, let us say Sand, for instance, it maintains its jaggedness. And this is crucial.

Your rocks are tumbling for days and this chemical compound holds its shape and continues to grind down, shape, and smooth out the rocks. It is like a relentless boxer, taking blows, but giving more back. Undaunted by the challenge of the opponent and able to maintain the resilience to win.

The chemical composition is crucial. and this goes for the polish also. The more resilient the polish, the more it keeps working.

Silicon Carbide Media Applications in addition to uses in rock tumbler, and this is why you are buying the product,  These include:

  • Gear Lapping Flat Lapping of Metals
  • Ceramics Glass Grinding
  • Abrasive Blasting Refractories 
  • Granite Polishing
  • Valve grinding
  • Compound lapping abrasives  Grinding of nonferrous materials
  • Finishing tough and hard materials 
  • Glass etching and glass carving