At first glance, both moonstone and opal might seem quite similar because they both exhibit a beautiful shifting of hues and light. But look a little closer, and you’ll be able to tell moonstone vs opal.
Moonstone, with its unique glow, seems to capture the soft light of the moon in a gem. Opal, on the other hand, is famous for its brilliant play-of-color, displaying an array of hues that change based on the viewing angle.
But it’s not just their appearance that sets them apart. There’s a lot to unpack about their formation, locations where they’re found, and even their fluorescence.
While they both enjoy a reputation for being enchanting, understanding the nuances of moonstone and opal can enhance our appreciation for each.
Moonstone vs Opal – The Major Differences
Moonstone and opal are like two artists with their own styles. While they might look or feel similar at first glance, they have unique characteristics that set them apart.
Appearance – Moonstone looks like moonlight on water
When you look at moonstone, you’ll see a magical effect: it shimmers and glows in a way that reminds many of moonlight. This effect, called adularescence, is what makes moonstone so special.
It’s like a soft, watery light dances just below the surface. The colors you usually see are blue, white, or sometimes even a rainbow sheen. It’s a gentle, calming glow that makes moonstone stand out.
Now, opal is a different story. It’s known for its play-of-color. When you move an opal under the light, it bursts with multiple colors, all at once. Reds, blues, greens, and more, all flashing and changing as you tilt the stone.
This vibrant display is what makes opals so mesmerizing. Instead of the soft glow of moonstone, opal is like a fireworks show trapped in a gem.
Colors – Opal comes in a wide range of colors
Moonstone has its own calm palette. It’s often found in cool shades of blue and white. Sometimes, if you’re lucky, you might stumble upon a moonstone with a rainbow sheen.
This means that as you move the stone around, you’ll catch hints of other colors, like pinks or yellows, but they’re usually pretty subtle. Think of moonstone’s colors as being gentle, soft, and often reminding you of a clear sky or a quiet pond.
On the other hand, opal showcases a wide range of colors, all packed into one gem. The colors in opals can jump from fiery reds and bright oranges to deep blues and forest greens.
Some opals even have all these colors at once! If moonstone is a calm, cloudy sky, then opal is a sunset on fire. It’s dynamic, always changing with the light, and can be quite the showstopper.
Luster – Moonstone shines like a piece of glass
Luster is like the finish on a freshly washed car; it’s all about how it shines. The lusters of moonstone and opal give each stone a unique charm.
Moonstone, with its dreamy vibe, has a luster that matches its character. It can be vitreous, which means it’s shiny like glass.
Sometimes, it leans more towards a pearly luster. Imagine the soft gleam you see on the inside of a seashell; that’s the pearly shine of a moonstone.
This type of luster helps give moonstone its gentle and calming appearance. It’s not super flashy but has a quiet, captivating beauty.
Now, opal is a bit of a wildcard. Its luster can vary. Some opals have a subvitreous luster, which is a tad less shiny than the vitreous one.
But many opals lean towards a waxy luster. Think of how a bar of soap or a candle looks when light hits it; that’s the waxy shine we’re talking about.
This waxy luster works great for opals because it complements the bright play-of-color inside the stone. It doesn’t overpower the colors but lets them take center stage.
Clarity – Opal ranges from transparent to opaque
Clarity in gemstones is all about how clear or cloudy they look. It’s like looking through different types of windows, some perfectly clear and others a bit foggy. If you compare opal vs moonstone, you’ll see some stark differences in clarity.
Moonstone is like that frosted window in your bathroom. It’s often transparent to translucent, which means you might be able to see through it a bit, or it might be slightly cloudy.
When you look closely at some moonstones, you might spot tiny lines or cracks inside. These are called centipedes. They aren’t actual bugs! They’re just tension cracks, and they give moonstone a bit of character.
Opal, on the other hand, is more unpredictable. Some opals are clear as day; you can see right through them. Others might be so cloudy that you can’t see through them at all, making them opaque.
This range in clarity means every opal is unique. While one opal might be as clear as glass, another could be as cloudy as a stormy sky.
Fluorescence – Moonstone can give off a blue glow under UV light
When we shine a special kind of light called UV (ultraviolet) on moonstones, many of them light up with a blue-white glow. This glow mostly shows up in the cracks or fissures of the stone.
But not all moonstones react the same. Under another type of UV light, some give off a faint bluish glow, while others might not light up at all.
Opals come in many types, and their fluorescence can be a bit unpredictable. Some opals, especially the black or white ones, can light up in colors like blue, green, or yellow under UV light.
Some might even continue to glow for a bit after the light is turned off, which is called phosphorescence.
Other opals might not light up at all, while some common opals might glow green or yellow-green. Fire opals, for example, could glow a greenish-brown or might not glow at all.
Crystal structure – Opal doesn’t have a regular crystal structure
Crystal structure might sound like a fancy term, but think of it as the building blocks or puzzle pieces that make up a gem. Moonstone and opal are put together differently, which is super interesting!
Moonstone’s building blocks are arranged in a specific pattern called monoclinic. Imagine setting up dominoes in a slightly slanted row, where they aren’t perfectly straight but lean just a tad.
That’s a bit like how the atoms and molecules are arranged in moonstone. This pattern gives moonstone its unique appearance and properties.
Now, opal is a whole different story. Instead of having a regular pattern like most gems, opal’s made up of something called amorphous silica. “Amorphous” is a cool word that means it doesn’t have a specific shape or order.
Picture dumping a box of different-shaped puzzle pieces onto a table; they’re all jumbled up without a clear pattern. That’s how opal’s building blocks are – a bit chaotic and random.
This lack of a regular structure is one reason why opals have those beautiful, flashy colors.
Cleavage – Moonstone splits in smooth flat surfaces
In the world of gems, cleavage refers to the way a stone breaks when you apply pressure to it. Moonstone and opal react differently, and here’s why.
Moonstone has what’s called “perfect cleavage” in one direction. Now, this doesn’t mean moonstone is super strong. In fact, it’s the opposite!
Because of this perfect cleavage, if you hit or drop a moonstone just right, it might split cleanly along that direction.
It’s like how wood splits along the grain. This makes moonstone a bit delicate, so you’ve got to handle it with care.
Opal, on the other hand, plays by its own rules. Remember how opal doesn’t have a regular pattern of building blocks? Because of that, it doesn’t have cleavage. It lacks a regular crystal lattice, so there’s no specific direction in which it will split neatly.
If an opal breaks, it might fracture in a more random way, not along a set path like moonstone.
Chemical composition – Opal contains water
Chemical composition is basically the recipe for each gem.
Moonstone is like a fancy salad with a mix of ingredients. Its official name is sodium potassium aluminum silicate. Now, that’s a mouthful, but it’s basically a combination of some common elements: sodium, potassium, aluminum, and silicate.
Mix these together in the right way, and you get the dreamy moonstone we all love.
A big difference between moonstone and opal is that opal is made of hydrated silica. Hydrated just means there’s water in there, and silica is a material found in a lot of rocks and sands.
Density – Moonstone feels heavier
Think of density as the amount of “stuff” packed into a certain space. It’s like comparing two boxes of the same size: one might be packed full of rocks, and the other might be only half full of rocks.
The full box is denser because there are more objects occupying its space.
Now, let’s look at moonstone. With a density ranging from 2.54 to 2.66 g/cm3, it’s got a pretty average density for a gemstone. Imagine it like a box mostly filled with small rocks but with a bit of space left over.
Opal, on the other hand, has a density of 2.09 g/cm3. This means it’s a bit less dense than moonstone.
The cool thing about density is that it can sometimes help gemologists figure out what kind of gem they’re looking at. By seeing how much a gem weighs compared to its size, they can get clues about its identity.
Formation – Opal forms in rock pockets
If you’re wondering where to go rockhounding for moonstone, there are specific regions known for their rich deposits of this gem. This gem starts its life in super hot places, specifically inside igneous rocks like granite.
Igneous rocks are formed from cooled and solidified magma or lava. As the magma cools down deep in the Earth, moonstone begins to take shape. So, you can think of moonstone as a gem that’s born from fire, in a way.
Now, opal has a different story. Imagine rainwater trickling down rocks, picking up tiny bits of silica along the way. Over time, this silica-rich water gets into cracks and little pockets in rocks.
Then, as the water evaporates, the silica is left behind and begins to harden. As this happens again and again, layers of silica build up and turn into the colorful opal we know.
Price – Moonstone is one of the cheapest gems
Moonstone and opal both have their own price tags, and they can be pretty different.
The value of moonstone can change a lot based on its quality. Think of it like shopping for apples: some might have blemishes, while others are perfect and shiny. The shinier and clearer the moonstone, the more you might pay.
Even the top-quality moonstones, the ones with that dreamy shimmer, can be quite wallet-friendly. Moonstone is one of the most affordable gems out there.
Ppals are a different story. They can get pricey, especially the really special ones. There are different types of opals, but the black and boulder ones are the stars of the show.
If they have a super vibrant play-of-color, their price can skyrocket.
Location – Opal usually comes from Australia and Ethiopia
Moonstone and opal are like travelers; they pop up in different parts of the world. Let’s take a journey and see where we might find them.
Moonstone has quite the passport. You could find it in places as diverse as Armenia, the sunburnt lands of Australia, the scenic Austrian Alps, and even in vibrant Mexico.
Let’s not forget spots like Madagascar, Myanmar, Norway, Poland, and the vast landscapes of the United States.
Once upon a time, if you wanted the cream of the crop, those super shiny blue moonstones, you’d head to Myanmar. But times change! Nowadays, Sri Lanka is one of the top sources.
On the other side, opal has its own favorite hangouts. Australia is the big name here; it’s like opal’s main home. But it also enjoys visits to Ethiopia and Mexico. Each of these places gives opal its unique look and feel.
You can also find opal deposits in the US. If you’re interested in finding gems near you, opal is primarily found in certain desert and volcanic regions.
Opal vs Moonstone – The Similarities
Moonstone and opal are both fascinating gemstones that people love. Even though they have their unique features, they also share some cool similarities.
After exploring what makes them different, it’s interesting to see what they have in common.
Streak – Moonstone and opal have the same streak color
Imagine taking a crayon and drawing a line on paper. Gems can do something similar. When you rub them on a rough surface, they leave a line or a “streak.” The color of this streak might be a totally different color than the gem itself!
Moonstone, with all its dreamy colors and glow, has a simple secret when it comes to its streak. Even if you have a moonstone that’s blue or rainbow-colored, if you were to test its streak, it would leave a white line.
Now, here’s where things get interesting. Opal, with all its fiery flashes and color dances, has the same streak as moonstone. This means that it also leaves a white line.
Hardness – The two minerals have a similar hardness
The Mohs scale is a measuring tape for gem hardness. The higher the number on the scale, which goes from 1 to 10, the tougher the gem.
Now, moonstone sits at a 6 on this scale. Imagine it like a student scoring 6 out of 10 on a test – not the best student in the class, but not the worst either.
This means you should be a bit careful when wearing moonstone jewelry. Banging it too hard might leave a scratch or chip.
Opal is in the same ballpark. Its hardness varies a little, falling between 5.5 and 6. This means some opals might be just a smidge softer than moonstones.
Since they’re close in hardness, both moonstone and opal need some care. It’s best not to wear them when doing heavy work or sports. They’re also not recommended for everyday wear.
Magnetism – Neither gem is magnetic
Magnetism is a force that pulls certain materials towards a magnet and can also push them away. It’s why magnets stick to the fridge and why some metals are attracted to them.
In the big, wide world of gemstones, there are some that are magnetic and some that aren’t.
Both moonstone and opal don’t play well with magnets. In fact, they don’t play at all! Neither of these gems is magnetic. So, if you tried to stick them to your fridge, they’d just slide right off. No magnetic attraction whatsoever!
Conductivity – Both minerals don’t conduct electricity
When we think about conductivity, our minds might go straight to metals, like copper or silver. These materials are great at letting electricity flow through them.
Moonstone isn’t much of a helper when it comes to conducting electricity. It’s like trying to pour water through a tight lid; it just doesn’t let much through. So, if you tried to use moonstone in place of a metal wire, you’d be out of luck.
Opal is on the same page. It doesn’t do a good job at letting electricity pass through either.
These two gems are pretty, shiny, and amazing in many ways, but don’t count on them to power up your gadgets!
The Easiest Ways to Tell Moonstone and Opal Apart
Moonstone and opal might seem similar, but they have clues that can help tell them apart. By looking at certain features, we can distinguish moonstone vs opal.
Examine the clarity
Clarity in gemstones is like looking through a window. Some windows might be a bit foggy, while others let you see through perfectly.
Moonstones, for instance, have a bit of a dreamy, foggy appearance. They aren’t usually crystal clear, and sometimes, you might even see little lines or cracks inside them.
So, if your gem has a soft, cloudy appearance with these unique little marks that look like fractures, it’s likely a moonstone.
Opals are a whole different story. Some opals are opaque. Others are so clear it’s like looking through pure water. When you hold them up, the clear ones will not only let light pass through but will also dazzle with their vibrant play of colors.
So, a gem that’s transparent, allowing you to see right through it, with a splash of bright, shimmering colors is probably an opal. It’s these differences in clarity that can help you figure out which gem you’re looking at.
Look for play-of-color
Color is one of the simplest clues you can use to differentiate between moonstone and opal. When you look at a moonstone, you’ll often see a gentle blue or white glow. It’s like the stone has a soft light inside it.
This beautiful effect, called adularescence, is what gives moonstone its dreamy look. Sometimes, a moonstone might surprise you with hints of other colors, but it’s usually this blue or white sheen that stands out the most.
Now, with opals, it’s a different story. They can be like little fireworks, bursting with a whole range of colors. Imagine tilting an opal and seeing a dance of red, orange, blue, and green flashes.
That’s the opal’s play-of-color. It can be so intense and varied that it looks like a tiny kaleidoscope.
So, if you’re trying to figure out which stone you have, remember: the soft, gentle glow points to moonstone, while a vibrant color dance suggests opal.
Ask about the origins
Knowing where a gem comes from can give you a big clue about its identity. If you’re shopping for a stone or someone’s showing you one, ask them about its origins.
For instance, if they mention places like Sri Lanka, India, or Madagascar, there’s a high chance you’re looking at a moonstone. These locations are popular sources for this dreamy, shimmering gem.
On the other hand, if they start talking about Australia, then you might be holding an opal. Australia is famous for its vibrant and colorful opals, especially from regions like Coober Pedy or Lightning Ridge.
Of course, opals can be found in other parts of the world too, like Ethiopia or Mexico, but Australia is the big name in the opal game.
So, the next time you’re curious about a stone’s identity, just ask where it’s from. It could give you the answer you’re looking for!
