KRCY Stage 3 Fine Pre-Polish Grit – 800 Aluminum Oxide

KRCY Stage 3 Fine Pre-Polish Grit is a professional-grade 500 mesh aluminum oxide abrasive formulated for the third stage of rotary rock tumbling.

This pre-polish grit is engineered to gently remove microscopic scratches and refine the surface texture left by Stage 2 medium grinding. It creates a smooth, uniform stone surface, improves polishing consistency, and is critical for preparing rocks to achieve a bright, mirror-like finish during the final polish stage.

Proper Stage 3 processing is essential because insufficient pre-polishing can lead to cloudy surfaces, reduced luster, or visible fine scratches even after the final polish. A well-executed pre-polish stage significantly enhances the final gloss, reflective clarity, and overall quality of tumbled stones.

The 800 mesh aluminum oxide delivers gentle, consistent cutting performance and forms a fine, stable slurry, helping users achieve cleaner, more uniform pre-polish results across medium-soft to medium-hard tumbling stones, including agate, jasper, quartz, and other semi-precious materials.

Recommended tumbling cycle:

• 5–7 days in a rotary rock tumbler (adjust based on stone hardness; extend 1–2 days compared to silicon carbide grit for optimal results)
• Water level slightly below the top of the stones
• Fill the tumbler barrel to 2/3 to 3/4 full with rocks (for optimal tumbling action)
• Clean rocks and tumbler barrel thoroughly before moving to Stage 4 polishing

Compatible with most rotary tumblers including:

• KRCY tumblers
• Lortone tumblers
• Thumler's tumblers
• Tumble-Bee systems
• Other standard lapidary rotary tumblers

Suitable for:

• Hobbyist rock tumbling
• STEM education projects
• Lapidary workshops
• Geological specimen preparation
• DIY gemstone polishing
• Professional stone tumbling projects

Store in a dry environment after opening.