Moonstone vs Opal: How These Gemstone Differ

For many people, the appearance of their jewelry isn’t complete without a gemstone attached to it. It’s hard to blame gemstone enthusiasts, as adding gems can elevate the beauty of all kinds of jewelry. Using either moonstone or opal on your jewelry can hardly be a wrong move as they are two beautiful stones.

What is Moonstone?


Moonstone, a member of the feldspar family, gets its name from its extraordinary visual qualities—looking at one is like looking at the moon itself. Moonstone’s unique and rather enchanting appearance means that it has been attributed spiritual significance throughout history. 

According to Hindu mythology, moonstone is created when moonbeams become solid. It was revered in ancient India and was linked to the gods of the moon by the Romans and the Greeks. When the moon was full, they thought holding a moonstone in your mouth would allow you to see into the future.

Between roughly 1880 and the start of World War I, the moonstone enjoyed particular vogue. This may be connected to the notion that the gemstone had spiritual powers, which were highly common back then. During the hippie movement of the 1960s, it rose to popularity again.

Moonstone Ring
Moonstone Ring

Moonstone is found in countries like Brazil, Madagascar, Tanzania, and Myanmar, with Sri Lanka and India as the two most notable places you can find them. Indian moonstone is renowned for its magnificent rainbow hues. On the other hand, the Sri Lankan moonstone is best recognized for its stunning blue tones, which are sadly becoming harder to locate.

Despite its name and membership in the feldspar family, Rainbow moonstone is a variety of labradorite. The most common type of moonstone comes from the mineral adularia, derived from a mining site in Switzerland called the Adular mountains. “Adularescence,” a word that describes the stunning appearance of moonstones, also derives from adularia.

The intergrowth of two different feldspars with varying refractive indexes causes adularescence. The adularescence can provide the appearance of motion as light moves across the gem’s surface, almost as if the rock has a spirit blazing from within.

What is Opal?


Opal is a kind of silicon dioxide that shares quartz’s chemical composition. Opal, on the other hand, is distinctive because it is highly hydrated, with its water content making up between 3 and 21% of the stone’s weight. Opal is a softer and more fragile stone than quartz because of its high water content.

Opal can be found in the fissures of practically any type of rock and is often deposited at a very low temperature. Gemologists classify the stone as an amorphous mineraloid because of its chemical composition, which means it lacks a clearly defined crystal structure.

Opal Ring
Sterling Silver Opal Ring

This stone is randomly distributed, with no discernible internal pattern, unlike a stone like quartz, which has a definite crystal shape. This dispersed nature is what gives beautiful opals their vibrant color play. The light will enter the stone and reflect off the sporadic particles inside, giving off the beautiful colors you see.

Opal’s transparency, translucence, and opaqueness can vary according to the conditions in which it formed. The background color can ultimately be white, black, or any other hue in the color spectrum. The most common opal colors are white, gray, and green. Black opals are the most uncommon and expensive.

Natural Australian solid Opal
Natural Australian Opal (Source: @Ben Zheng)

Australia and Ethiopia are the primary sources of opal. However, due to conflicting extraction claims, determining which of the two countries dominates the market has been challenging. Additionally, it is challenging to compare the output of the two nations due to the disparate measurement systems.

Comparing Moonstone and Opal

Moonstone vs Opal

Moonstone and opal are two beautiful stones with some visual similarities, making it easy to mistake them for each other. However, there are some differences between both stones.

1. Chemical Composition

These two stones have entirely different chemical compositions. One of the planet’s most widely distributed mineral groups, the feldspar group, includes moonstone. It is composed of albite and orthoclase; opal, on the other hand, is a byproduct of the mixture of water and silica. So while some moonstones might look like opal, their makeup is very different.

2. Appearance

Both moonstone and opal play with light in distinctive ways. Still, moonstones have a schiller effect called adularescence that results from light scattering as it passes through the stone, giving it a bluish color or luster.

Black Moonstone
Raw Black Moonstone

When you examine a Moonstone crystal closely, you will notice a soft light that emanates from underneath the gem’s surface and is reminiscent of the moon’s glimmer on a sea surface at night. Adularescence is centered around this.

Rainbow Moonstone
Rainbow Moonstone

Similar effects are known as “opalescence” in opals, but this is more of a play of light that produces various milky, blue, and orange lusters based on the numerous microscopic silica spheres in their chemical composition.

3. Colors

Moonstones come in various colors, including pink, peach, green, yellow, brown, grey, and blue, although they can also be colorless.

Peach Moonstone
Raw Peach Moonstone

On the other hand, Opals triumph over moonstone and the gemstone’s singularity because there is no identical Opal in the world. Opals can be found in various colors, including white, black, and orange, with numerous flashes of different hues.

Green Opal
Raw Green Opal

4. Hardness

Compared to moonstone, opal is softer and more susceptible to damage. According to the Mohs scale of mineral hardness, opals range in hardness from 5.5 to 6.5, meaning they are fragile stones that you need to handle with care. 

Raw Moonstone

Moonstone fares slightly better with a range of the hardness of 6 to 6.5; it’s a little stronger than opal but prone to scratching and breaking. So, regardless of which gem you choose, remember that if you intend to use these beauties daily, you will need to take extra care of them.

5. Significance of the Stones

Moonstone is linked to new beginnings, love, intuition, and personal growth. Additionally, it aids in reducing stress and bad emotions. Moonstone is excellent in lowering anxiety levels.

Opals, on the other hand, promote independence, creativity, and a stronger drive to live. Opal increases feelings and lets go of inhibitions and fury. Because of this, this gem is regarded as a jewel of passion and love. However, some people associate opals with bad luck and would rather wear any other gemstone but this one.

Moonstone vs Opal Price

The price of a moonstone varies from $5 to $50 per carat. It may be less than this, but since the distinction between the gemstone quality material is a little hazy, there may occasionally be some confusion on the lower end of the spectrum. A moonstone’s range will vary depending on its categorization, typically determined by how well the stone exhibits its quality of adularescence.

The table below shows the price of different types of moonstone.

TypeCost per Carat
Moonstone$1.30 – $15
Cat’s Eye Moonstone$3 – $50
Rainbow Moonstone$5 – $60
Star Moonstone$2 – $30
Source: How To Find Rocks

In general, opal is a more valuable stone; however, the rarity and beauty of the type of opal determine its value. The black opal, which is exclusively found in Australia and may cost up to $10,000 per carat, is the most expensive variety of opal. However, you can purchase blue and common pink opals for as little as $7 per carat.

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