Moonstone is a type of feldspar, the same family as sunstone and labradorite. Moonstones are commonly found in Sri Lanka – especially the finest blue moonstones.  There is some confusion with moonstone in the jewelry world – the popular “rainbow moonstone” mined in India is geologically speaking, not moonstone but labradorite.  The term “rainbow moonstone” however is a widely accepted trade name.

The Most Valuable Moonstone

The most valuable moonstone has a strong glowing  blue color that flashes and moves inside the stone. It is free of inclusions (impurities or internal cracks), perfectly polished and large (over 5 carats).


Low Value: These brownish greyish moonstones are not particularly beautiful or rare. They usually sell for around $10 -$20 for small stones 1 to 3 carats in size. Medium Value: This is a lovely moonstone. It has an uninterrupted colorful glowing sheen. Moonstones like this are what you typically find in nicer jewelry. For a small stone (1 to 3 carats) the price will be under $100. Stones that look like this that are large (over 10 carats) can sell for thousands. Medium Value: These peach moonstones are becoming popular. The more saturated and “peachy” the color is, the better.  Also look for a nice white sheen (adularescence) – some pea moonstones can look dull without it. Highest Value: This moonstone shows very vibrant blue color. The color is continuous: there are no inclusions. It is also very large at 8 carats. A fine gem large gem like this will cost in the thousands.

Some More examples of moonstones:

Cat's Eye Moonstone

This is a perfect, lovely (huge!) cat’s eye moonstone. Now and then a gemstone is able to show a phenomena wherein tiny inclusions in the stone line up perfectly in one direction so that when light hits it, it shows a solid white line, called a “cat’s eye”. Moonstones can produce a cats eye more easily than most gems, but a cats eye is still relatively rare and will be a bit more expensive.


Star Moonstone

Occasionally, a moonstone will show a 4 pointed star, as shown here. This is not very common – much more rare than the cat’s eye. Moonstone is probably stone y the only stone you will ever see with a 4 point star (most have 6 or 12). A star Moonstone will be much more valuable (maybe 10 times more) than a similar stone without a star.

Here is another example of the best, most expensive kind of moonstone in the world. A 13 carat blue moonstone from Sri Lanka.

Rainbow Moonstone

This is the “rainbow moonstone” – a cousin of moonstone that is technically labradorite. This one shows lovely color and interesting angular patterns, but also has a lot of inclusions and cracks. A stone like this will usually cost $20-$30 in medium size.

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