20 Pounds 12,000 Grit Sub Micron Aluminum Oxide Polish - Extreme

In this review the focus is on whether MJR Tumblers' 20 pound bag of 12,000 grit sub micron aluminum oxide polish is worth adding to a tumbler shop or hobby bench. The bottom line: this product is for finishers who need an ultra-fine final polish and want consistent, high-gloss results; it delivers markedly finer abrasive action than common 1,200 or 1,500 grit alternatives and can replace multiple steps in a polishing sequence when used correctly.

Key Features

• Ultra-fine 12,000 grit: The extremely fine particle size produces a much smoother finish than coarser grits, improving final shine on stones and metal pieces.
• Sub micron formulation: The sub micron aluminum oxide helps reduce micro-scratches and produces a cleaner, more reflective surface during that last polishing stage.
• Large 20 pound quantity: The bulk size is practical for hobbyists and small shops that polish frequently and need a reliable supply without frequent reordering.
• Consistent performance: The exclusive polish is formulated to deliver repeatable results across batches, which helps standardize finishing workflows.
• Veteran and disabled owned brand: The company background may matter to buyers who prefer to support veteran and disabled owned businesses.

Who It's For

This product suits experienced rock tumblers, lapidary hobbyists, and small finishing shops that perform a dedicated final polishing step and want the finest abrasive available in a bulk bag. If you already use 1,200 or 1,500 grit final compounds and find the shine lacking, upgrading to this 12,000 grit polish can produce noticeably better reflection and surface smoothness.

Beginners who are still learning tumbling sequences or who prefer a simpler, lower-cost approach may prefer smaller quantities or multi-step kits before investing in a 20 pound bag. Also, users expecting dramatic results without proper technique or rinse cycles may be disappointed; correct use is important to achieve the promised finish.

Pros & Cons

Pros

• Delivers an ultra-fine final polish that reduces micro-scratches and enhances shine.
• Large 20 lb supply is cost-effective for frequent polishers and small shops.
• Consistent sub micron formulation that helps standardize results.

Cons

• Some customers report mixed polishing outcomes when technique or expectations differ, yielding a more matte finish in certain cases.
• The bulk quantity may be excessive for casual users who polish infrequently.

Specifications

Our Verdict

For serious hobbyists and small shops that require a premium final polish, this 12,000 grit aluminum oxide powder is a practical, high-value choice because it is far finer than standard 1,200 or 1,500 grit compounds and produces superior finish when used properly. Casual users should consider smaller quantities or confirm technique first, but for those committed to top-tier shine the bulk bag is hard to beat.

Frequently Asked Questions

Will this replace lower grits?
It is designed as a final polishing step; it does not replace coarse grit stages but can reduce the need for intermediate polishing steps if surfaces are prepped properly.

Is the 20 lb size suitable for hobbyists?
It is ideal for frequent users and small shops; occasional users may find the quantity larger than needed.

Are results consistent?
Formulation aims for consistent performance, though final shine depends on technique, cleanliness, and proper use of tumble cycles.