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Tumbling Moonstone: Factors Tips and Choosing Tumbling Mates

Tumbling Moonstone and

Choosing Tumbling Mates

Have you ever come across a moonstone gem, and wondered why it shimmers like the moon? Moonstone is a member of the feldspar family and is known for its iridescent play of color, which is known as adularescence.

Moonstone is also believed to carry powerful metaphysical properties. If you are a rock lover or jewelry maker, you may want to tumble your moonstone to bring out its best qualities.

This article will discuss factors that affect tumbling moonstone, along with tips for polishing moonstone. We’ll also talk about the importance of choosing the right tumbling mates, and the recommended minerals to tumble with moonstone.

Factors That Affect Tumbling Moonstone

Before we proceed to tumbling moonstone, let’s take a closer look at the gemstone itself. Moonstone is a mineral variety of feldspar that has a hardness of 6 to 6.5 on the Mohs scale.

The internal structure of moonstone makes it prone to fractures and cleavage, which can affect its durability. Therefore, it is essential to handle moonstone with care.

When tumbling moonstone, several factors can affect the outcome of the process. The first is the hardness of the tumbling medium.

Moonstone should be tumbled with a medium that has a hardness equal to or greater than its own. Tumbling media that are too soft may scratch the gem, while those that are too hard may grind it down too quickly.

Another factor that can affect moonstone is the tumbling companions. Tumbling moonstone with other hard gemstones can cause them to rub against each other, producing unwanted blemishes and scratches.

Therefore, it is essential to choose tumbling companions that are not too hard or abrasive. The grit and polish used for tumbling can also affect the quality of the moonstone.

The grit should be coarse enough to remove surface imperfections and polish the surface gradually. Polishing should be done with a fine polish that will give the stone a shiny finish.

Finally, the burnishing and cleaning of the moonstone can also affect its outcome. Burnishing smooths out any rough edges or surfaces, while cleaning removes any leftover grit or polish that may remain on the stone.

Tips for Polishing Moonstone

Now that we understand the factors that can affect moonstone tumbling, let’s look at some tips for polishing moonstone. The first step is to use a tumbler that has a rubber barrel to prevent the moonstone from bouncing around and hitting other stones in the tumbler.

The tumbler should be filled with a tumbling medium that has a hardness of 7 or less, such as plastic pellets or ceramic cylinders. The ratio of stones to tumbling medium should be 1:1.

Start with coarse grit, such as 80 mesh silicon carbide. Add enough grit to cover the stones.

The tumbler should be run for approximately one week, checking the progress regularly. If the stones are not polished enough, add more grit, and continue tumbling for another week.

After the stones are polished, a fine polish is applied to them. 1200 mesh aluminum oxide is a popular fine polish.

A small amount is added to the tumbler with distilled water, and the stones are tumbled again for another week. Once the stones are polished, they should be burnished to remove any rough edges.

Burnishing can be done with a stainless-steel shot, mixed with water and a small amount of dish soap. The tumbler should be run for about 24 hours.

Finally, the stones should be thoroughly washed and rinsed with distilled water. The water should be changed several times to ensure that no leftover grit or polish is left on the stones.

Choosing Tumbling Mates

Choosing the right tumbling mates is critical to ensuring that your moonstone stays in good shape throughout the tumbling process. Labradorite, Microcline, Sunstone, Nephrite, and pyrite are some minerals that will tumble well with moonstone.

Labradorite is a member of the feldspar family and occurs in shades ranging from pale green to blue-gray. It is a popular tumbling mate for moonstone due to its hardness and striking blue shimmer.

Microcline is another member of the feldspar family and shares many properties with moonstone. It has a hardness of 6 to 6.5 on the Mohs scale and is popular for its beautiful salmon-pink color.

Sunstone is a type of feldspar that ranges in color from orange to brown. It has a hardness of 6 to 6.5 and has a shimmering effect that can enhance the beauty of the moonstone.

Nephrite is a type of jade that has a hardness of 6 to 6.5 on the Mohs scale. It has a smooth texture and can be polished to a high gloss when tumbled with other stones.

Pyrite is a brilliant golden mineral that has a hardness of 6 to 6.5 on the Mohs scale. Its metallic luster complements moonstone and adds a beautiful contrast to the composition.


In conclusion, tumbling moonstone and choosing tumbling mates are essential aspects of gemstone preparation. Tumbling moonstone can bring out its best qualities, and choosing the right tumbling mates can ensure that the gemstone stays safe during the process.

By following the tips outlined in this article, you should have a better understanding of the factors that affect moonstone tumbling and the recommended tumbling mates for moonstone. Choosing Stones Carefully: Factors to Consider When Tumbling Moonstone

When selecting moonstone to tumble, there are several factors to consider.

One essential factor is the presence of internal fractures. Moonstone contains internal striations known as Schiller, which gives the stone its iridescent quality.

However, if the Schiller is fractured, it can make the stone brittle and prone to breakage. When choosing moonstone to tumble, ensure that the stone is free of large internal fractures.

Another factor to consider is the quality of the specimen. Solid, high-quality moonstone will hold up better during the tumbling process than a thin or poorly-formed specimen.

Make sure to inspect the moonstone carefully before placing it in the tumbler to ensure it is solid and resilient. Using High-Quality Grit: Impact of Using Low-Quality Grit

The quality of the grit used in tumbling is essential to the outcome of the process.

Low-quality grit can contain larger, irregular particles that can scratch or damage the stones being tumbled. The consistency of the grit is also crucial.

Inconsistent grit can create uneven tumbling, resulting in an unsatisfactory finish. When using low-quality grit, it may take longer to achieve the desired finish, and even then, scratches and nicks may remain.

The particles in the grit can be too large and abrasive, wearing down the stones too quickly. A quality tumbler grit will be consistent in size, have a smooth, angular shape, and be free of impurities.

Recommended Brands of Grit

One brand of grit that has been consistently praised for its quality is the Rock Shed. They offer a range of tumbler grits, from coarse to fine, that is suitable for various types of gems.

The grit is made from high-quality silicon carbide, which is hard-wearing and long-lasting. The Rock Shed grit is also known for its consistency in size, ensuring even tumbling with a smooth finish.

National Geographic is another brand known for its high-quality tumbler grit. They offer a range of grits suitable for various types of gems, including silicon carbide, aluminum oxide, and diamond.

Their grit is free of impurities and has a consistent particle size for even tumbling.


Choosing stones carefully and using high-quality grit are essential aspects of tumbling moonstone. When selecting moonstone to tumble, ensure that the stone is free of internal fractures and of solid quality.

Additionally, using high-quality grit will result in an evenly tumbled and polished stone with a smooth finish. The Rock Shed and National Geographic are two brands that offer quality grits suitable for tumbling moonstone.

By keeping these factors in mind, you can achieve a beautiful, polished result when tumbling your moonstone. Knowing Your Polish: Choosing the Right Polish for Tumbling Moonstone

Choosing the right polish for moonstone is crucial to achieve the desired final result.

A good polish should be able to remove any remaining roughness and scratches on the surface of the stone while leaving behind a bright and consistent shine. The grit used for the polishing stage for moonstone should be ultra-high grits, typically around 50,000 grit.

For the final polish, a cerium oxide polish is a popular choice for moonstone. This type of polish is water-soluble and can be mixed with distilled water for use in rotary or vibratory tumblers.

Once the cerium oxide polish is added to the tumbler, the stones should be tumbled for at least 24 hours. Afterward, the stones should be rinsed thoroughly with distilled water to remove any leftover polish residue.

Burnishing Cycle: Using Stainless Steel Pins and Borax with Flaked/Grated Ivory Soap

After polishing, a burnishing cycle is recommended for moonstone to ensure that the stone has a high gloss and is free of any rough edges or blemishes. Burnishing is a process that involves adding stainless steel pins to the tumbler, along with a burnishing mixture.

The mixture typically consists of borax and flaked or grated Ivory Soap. As the tumbler rotates, the pins and mixture work together to burnish the surface of the stones.

The burnishing cycle should run for around 24 hours. After the burnishing cycle is completed, the pins should be removed, and the stones washed and rinsed thoroughly with distilled water to remove any leftover burnishing mixture.

Using Distilled Water: The Importance of Using Distilled Water for Polishing and Burnishing Stages

Distilled water is crucial to use during the polishing and burnishing stages of tumbling moonstone. Regular tap water contains minerals and impurities that can leave behind unwanted deposits on the surface of the stones.

Over time, these deposits can build up and dull the shine of the polished stones. Distilled water is free of minerals and impurities, making it an excellent choice for use in the polishing and burnishing stages of tumbling.

It ensures that the final result is free of any unwanted residues and streaks, with a bright and consistent shine. Calcium deposits are common in areas with hard water.

If tap water is used for the polishing and burnishing stages, calcifications can adhere to the stones, affecting their luster. These deposits can also accumulate in the tumbler, affecting its mechanical parts.

Distilled water should be used to prevent this occurrence.


Knowing your polish and using distilled water during the polishing and burnishing stages of tumbling moonstone is essential for achieving high-quality results. The right polish can provide a consistent shine while removing any leftover roughness on the surface of the stones.

A burnishing cycle using stainless steel pins and a borax and flaked or grated Ivory Soap mixture helps ensure that the stones have smooth edges and a high gloss. Distilled water is essential for removing unwanted residues and streaks, preventing calcium deposits, and maintaining the shine of the polished stones.

By keeping these factors in mind, you can tumble beautiful moonstone with consistent results. In conclusion, tumbling moonstone requires careful consideration of factors such as choosing the right stones, using high-quality grit, and polishing and burnishing using the correct techniques and materials.

The use of distilled water also plays a critical role in preventing unwanted deposits and maintaining the shine of the polished stones. By taking these factors into account and following the recommended guidelines, you can achieve beautiful, consistently polished moonstone.


– Can moonstone be tumbled with other gemstones? Yes, but it’s crucial to choose companion stones that are not too hard or abrasive.

– What is the recommended polish for moonstone? Cerium oxide at an ultra-high grit of around 50,000.

– How long should moonstone be tumbled with polish and burnishing mixtures, and what are the recommended products to use? Polishing should run for about 24 hours, and recommended products include a borax and flaked or grated Ivory Soap mixture for burnishing.

– Why is distilled water recommended for polishing and burnishing stages? Distilled water is free of minerals and impurities, preventing unwanted residues, streaks, and calcium deposits on the surface of the stones.

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