Rock Tumbling Grit - Stage 1 Coarse 60/90 Grit - Silicon Carbide

Our 60/90 silicon carbide is a Stage 1 coarse tumbling grit for rotary tumblers, used to shape rough rock, remove weathered outer surfaces, round sharp edges, and prepare stones for the later stages of tumbling. If you want smooth, well-shaped stones that are ready for medium, fine, and polish, this is where the process starts.

A good polish begins with a good coarse grind. Skip this stage or rush it, and the flaws usually show up later.

What Stage 1 Grit Does

Stage 1 is the shaping stage. This coarse grit helps:

• Remove weathered rind and rough outer surfaces
• Round off sharp edges and corners
• Smooth rough texture and surface irregularities
• Begin shaping rough rock into tumble-ready stones
• Prepare rocks for Stage 2 medium grit and later polishing stages

For many batches, Stage 1 is the longest and most important step. Some rocks need more than one coarse run before they’re ready to move on.

Best For

Use this grit when you want to:

• Start a new batch of rough rock in a rotary tumbler
• Shape and smooth freshly collected stones
• Remove weathering, rind, and damaged outer surfaces
• Round angular rocks before finer stages
• Build the foundation for a better final polish

Not For

This grit is not for:

• Final polishing
• Pre-polish
• Quick shine improvement
• Vibratory finishing stages
• Skipping straight to glossy results

If you want bright, polished stones, this is the beginning of that process — not the end.

Rotary Tumblers Only

This 60/90 coarse grit is intended for Stage 1 use in rotary tumblers. It is designed for aggressive grinding and shaping at the start of the tumbling process.

If you're working through a full tumbling cycle, this is your first step before moving on to medium, fine, and polish.

How to Use It

For most rotary tumbler batches:

• Fill the barrel about 2/3 to 3/4 full
• Use a mix of rock sizes for better tumbling action
• Add about 1 tablespoon of grit per pound of rock
• Add water until it is just visible among the top layer of stones
• Run the batch, then inspect the rocks carefully before moving to the next stage

If your stones still have pits, cracks, rough texture, or weathered areas after one run, they likely need another Stage 1 cycle.

How Much Do You Need?

The right size depends on how often you tumble and how much rough you process.

• Sample - 2 oz: good for testing or very small batches
• Small Bottle - 8 oz: good starter size for occasional tumbling
• Medium Bottle - 16 oz: a solid all-around size for regular hobby use
• Large Tub - 32 oz / 3 lb: good value for frequent tumbling
• Bulk Bag - 10 lb or 25 lb: ideal for heavy use, repeat Stage 1 runs, clubs, classrooms, or serious hobbyists

Because coarse grit is often used for multiple runs, many tumblers go through more Stage 1 grit than any other stage.

Why Coarse Grit Matters

The quality of your later stages depends on how well you do this one.

Medium grit, fine grit, and polish won’t fix rocks that still have deep pits, rough areas, or weathered surfaces. A proper Stage 1 run helps create smoother, more even stones that are ready for the rest of the tumbling process.

In other words: better shaping now means better polish later.