Moonstone vs Opal: Factors That Make The Difference

Want to know the difference between moonstone and opal?

You're in the right place. 

In this Learning Guide, I'll answer the most popular questions about these two stones like: 

moonstone vs opal
  • Is Moonstone A Durable Gemstone?
  • Are Pink Opals Real? 
  • Is Opal Good for an Engagement Ring?

Main Differences between Moonstone vs Opal

  • Moonstone shows adularescence, whereas opals show opalescence.
  • Opals show a rainbow of colors, whereas moonstone glow white or blue.
  • There are no lab created moonstones, whereas lab created opal is common.
  • Opals can go for thousands of dollars, whereas fine quality moonstone goes for hundreds.

Moonstone vs Opal: Origin

Moonstone

There are two types of moonstone out there. Most people familiar with the stone don't realize rainbow moonstone is not the same as natural moonstone. They also might not know that rainbow moonstone isn't a moonstone at all.

Rainbow moonstone is part of the labradorite gemstone species. Moonstones are an orthoclase variety. Natural moonstone is made up of two minerals: albite and orthoclase. Both moonstone and rainbow moonstone are part of the feldspar group, but they are more like cousins.

real moonstone
rainbow moonstone

Natural moonstone gemstones can be found in Sri Lanka, India, Australia, Mexico, Brazil and Armenia. Most rainbow moonstone comes from India and Madagascar.

Moonstones are one of top trendiest stones in gemstone jewelry. They're most associated with the moon (go figure). Ancient cultures believed moonstones were solidified moon beams captured into a gemstone. They also believe moonstone jewelry to be a feminine stone.

Many women wore moonstone to increase fertility and protect their children.

Today, the spiritual properties of moonstone are said to help with fertility, new beginnings, parenting, inner purity, healing your inner self, bringing confidence, enhancing intuition and dispelling negative emotions.

Opal

precious opal

credited: James St. John

Opal is another popular gemstone today. Many people are familiar with it as the birthstone for the month of October. It's also the national gem of Australia. Many opals are found in the Australian subcontinent.

Opal gems are formed in compounds of silicon dioxide and then found in water deposits. After the tiny silica spheres form, different minerals mix with them when water flows through area. The minerals are tumbled by the water, creating opal stones.

The minerals tumbled also mix with other non opal material to create opalized wood, jasper opal, agate opal, and opalized petrified wood. When opals are still left in their original matrix stone, they're called boulder opals.

fossil opal

credited: cobalt123

Opal jewelry is more popular than using opals for their healing properties. Still, it's believed that opal intensifies emotions and has a high vibrational energy. It is believed to bring balance, increase energy and creativity, as well as bringing good karma.

You can find opals in Australia, India, Ethiopia, and Mexico.

Moonstone vs Opal: Appearance

Moonstone

white moonstone

credited: Mauro Cateb 

different color moonstone

credited: beautifulcataya

Genuine moonstone occurs in a variety of colors, but the most sought after ones are white and blue moonstone. Other colors of moonstone include white, beige, brown, creamy yellow, reddish brown, grey, blue, peach, and pink. A rainbow moonstone crystal has a translucent to transparent white body color with rainbow flashes.

Moonstones with white and blue color flashes have adularescence, a type of schiller effect. To show this optical phenomenon, the stones must be cut into cabochons. If tilted at certain angles under direct light, you'll see a bright blue flash in the stone.

This is caused by scattered light passing through the stone. White moonstones tend to have more of a faint glow.

Synthetics & Imitations

Moonstone is a common material, so there's no real need to synthesize it. Blue ceylon moonstone is more rare, but it's hard to replicate this unique stone. Instead, a moonstone is often confused or imitated by other gems.

The most common is rainbow moonstone and moonstone. Moonstone and opal are often confused with each other because they both display color flashes when turned at an angle. They also have a similar translucent white color. But there are some significant differences between the two stones.

Opal

Opals are characterized for their translucent milky white body color. However, not all opals are white. The most prized opals come from Lightning Ridge Australia. Black opals are the most valuable, which have a dark blue to gray color. Mexican opals, also known as fire opals, have an orange base color.

faceted black opal

credited: James St. John 

faceted fire opal

credited: Captain Tenneal

play of color opal

credited: rockman836 

Both moonstone and precious opal are cut en cabochon in order to display their color flashes. The exception to this is Mexican opals, which are faceted for their fiery orange gems. Moonstones have adularescence, but opals have opalescence. The chemical structure of the opal will diffract light, causing color flashes.

No two opals are the same.

When you angle an opal, you see its play of color. Different patterns occur across the body color. Generally, you will see yellow, green, and orange colors across the surface. Opals with play of color are called precious opals.

Synthetics & Imitations

Lab created opals are commonly found at mall jewelry retailers like Kay and Zales. You can find both blue opal and pink opal at these stores. Pink opal is lab created, but there is such thing as a blue opal. Blue Peruvian opals have a bluish green body color, but no play of color. Lab created blue opals have play of color.

The biggest imitation gemstones for opals are opalite and rainbow moonstone. Opalite is a man made glass with an iridescence. They don't exude any color flashes and are significantly less valuable than a precious opal.

Rainbow moonstone and opal can look a lot alike, especially if both are faceted. Rainbow moonstone doesn't have the same bright flashes as precious opal.

Read also: Opalite vs Opal

Moonstone vs Opal: Price & Value

The prices between a moonstone and opal differ depending on the quality. The feldspar group is one of the most widespread minerals in the world. Low quality moonstones are very common, but high quality ones are not.

Still, even a rare Ceylon moonstone with strong adularescence goes for around $40 per carat.

Opals are a different story. The cost of an opal is more of an art than a science. Opals aren't rare, but stones with uncommon patterns may be valued more. Black opals are the most valuable. Fine color specimens can go for up to $8,000 per carat.

Lab created opals are very affordable, less than $50 per carat. Fire opals go for around $100 per carat.

Overall, opals can run between $50 to $8000 per carat.

An opal isn't a very hard stone, neither is moonstone. Even though many express desires of wanting opals and moonstones for engagement rings, it's not a great idea. Both stones are easily scratched.

Mohscale

Image by the National Park Service. Public Domain.

On the mineral scale of hardness, opal is about a 5.5-6. Moonstone reaches a 6-6.5. Moonstone's mineral hardness is slightly better than opal, but not by much. The Mohs scale measures the scratchability level of a mineral. Diamonds are the hardest mineral, reaching a 10 on the scale.

Moonstone also has gemstone cleavage, which means it has a high percentage of being cracked if hit in the wrong spot. For a stone you'll want to wear every day in an engagement ring, you'll want to be careful with either of these. And be prepared to replace them if they get damaged.

Conclusion

There are lots of similarities between moonstone and opal. There are some key differences as well.

Opals are made from silicon dioxide in water deposits. Natural moonstone and rainbow moonstone are both feldspar minerals with different chemical formulations.

Moonstones exude a blue or white glow, while opals display orange, yellow, and green flashes.

Both of these stones are fragile stones and can easily be damaged if worn frequently. They make beautiful jewelry, but should be worn sparingly and with care.

I hope I've helped you sort out the difference between opal and moonstone. Both gems are worth adding to your collection for their unique gemstone phenomena.


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