Star Sapphire Buying Guide – Asterisms and Prized Inclusions

Star Sapphire Buying Guide – Asterisms and Prized Inclusions

You’re at the right place if you’re looking to buy star sapphire stones. Keep scrolling!

This guide explores everything you need to know about star sapphire gemstones. We’ll also answer some of the most frequently asked questions about them including:

  • How to I choose the best star sapphire gemstones?
  • Is star sapphire expensive?
  • How can I tell if a star sapphire is fake or real?

Let’s dive in, shall we?

Star Sapphire Buying Guide – Asterisms and Prized Inclusions

What Are Star Sapphire Gemstones?

Most average jewelry buyers tend to assume that all star sapphire gemstones available on the market are fake. This is because star sapphires look quite different from regular faceted blue sapphire stones. However, star sapphires are real sapphires usually made from corundum mineral.

Star of Asia Star Sapphire at the Smithsonian Museum

Star sapphires are always cut differently as compared to faceted sapphire engagement rings. The rough sapphire is usually cut en cabochon as opposed to faceting angles. Most gemstones are cut en cabochon but only a few of them can take up a star shape.

Star sapphires get their name from the famous six rayed star which appears in sapphire cabochons. They tend to exhibit asterism – an optical phenomenon. Like star sapphires, their faceted counterparts also have inclusion that can cause the star effect especially when cut en cabochon.

Chatoyancy vs. Asterism in Gemstones

Asterism is linked to a different gem phenomenon known as Chatoyancy. Chatoyancy in layman terms is typically the cat’s eye effect. Rather than casting a star shape when cut en cabochon, the rutile silk inclusions in the stone produce a glowing sheen. The rutile silk looks like the eye of a cat and that’s where the name was derived from.

Asterism in Pink Sapphire and Blue Sapphire. Chatoyancy in Yellow Sapphire

Asterism is a star effect. Besides, the stars normally have different rays. Technically, it’s supposed to display a six rayed star sapphire. However, there are star gemstones with more than six rays. There are 12 rayed star sapphire stones albeit rare.

Star Rubies vs. Star Sapphires

When thinking about sapphire engagement rings, most people think of a blue sapphire center stone. Blue sapphire stones are the birthstone for those born in September. However, sapphires occur in a wide range of colors and colorless is no exception.

Fancy sapphire stones are gems with colors other than white and blue. It’s almost comparable to how fancy colored diamonds are frequently used to describe colored diamonds. However, other gemstone colors can equally exhibit the star effect. Black, pink, blue and purple star sapphire stones tend to do it more frequently.

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Some yellow sapphire stones also exhibit asterism although it’s difficult to perceive a rayed star in the reflection.

Red is the only shade in which sapphire stones don’t come in. This is owing to the fact that ruby is an alternate name for red corundum. As a result, they are known as star rubies and not red star sapphire gemstones.

Star Ruby

Where Can You Find Star Sapphire Stones?

You can find high-quality star sapphires in a variety of corundum deposits all over the world. Most countries can produce rutile inclusions including Madagascar, Myanmar, Sri Lanka, Thailand, Australia, and Brazil.

Choosing a High-Quality Star Sapphire

There are a few things you need to factor in when looking for high-quality star sapphire stones available on the market regardless of the color. Here are some tips:


You might want to check if the stone in question is legit especially if it’s being sold at a higher price. And this is where gemstone grading reports come into play. These reports will help you know the origin, treatments and grades of the star sapphire stone.

However, some sellers can easily come up with a fake certificate. In this case, it would be best to ensure that the jewelry industry recognizes the certifying lab.


It’s pretty much self-explanatory. Ensure there are no irregularities or deformities in the shape by observing the domed cabochon. Look for dents, cracks or chips throughout the gemstone. You might want to check the stone’s HD images and 360-degrees videos when shopping online.


Some of the best star sapphire gemstones usually come with needle-like inclusions that produce a well-defined star. However, you can find other inclusions in corundum. Darker mineral inclusions tend to create vivid dark spots on the cabochon bringing down its value. As you know, less valuable stones are relatively cheap.

Light Performance

The drawback of not seeing the star sapphire stones in person or in 360-degree video is that photos can be deceptive. When looking through a wide selection of blue sapphire stones with noticeable star effects, you’ll be surprised to realize that star blue sapphire stones look entirely different in reality especially under some lighting.

You can see the star effect quite clearly when you tilt the stone from left to right. The prominence of the star along with the fact that its looks glowy instead of a solid look-like in photos can be seen by observing its light performance.

Carat Weight

You might need to go for a star sapphire with a bigger carat weight especially if you want it for its distinctive look. Even though they’re relatively cheap, star gemstones below a carat makes it harder for one to see the stone’s star effect.

En cabochon cut gemstones, on the other hand, stand out regardless of their setting. A star sapphire engagement ring is therefore, increasingly susceptible to damage owing to its increased carat weight.

Are Star Sapphire Stores Expensive?

Sapphire stones come in different colors and they display asterism. However, the best blue sapphire gemstones are those with the star effect. Black star sapphires, on the other hand, command value more than their faceted counterparts.

Black Star Sapphire

Star sapphires with large carat weights are usually more expensive. However, they are cheaper in low carat weights between ½ to 1 carat.

High-quality star sapphire stones between 1 to 5 carat usually go for up to a maximum of $1200 per carat. Other different sapphires colors including yellow sapphires can go for $500 per carat and beyond in this particular range of sizes. Lastly, black star sapphire stones of the same size go for $30 per carat.

Best Places to Buy Star Sapphires Stones

Since star sapphires are not frequently sold at the same stores that sell engagement rings and diamonds, buying one can be quite challenging. For this reason, you might encounter local jewelers or individual sellers that can help you source the stone or have it in stock.

Natural Sapphire Company is one of the most reputable online jewelers with a wide range of natural star sapphire stones. They also provide videos so you can see how the gemstones look under some lighting.

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How to Determine Whether a Star Sapphire is Real or Fake

Fine star sapphires cut from real sapphire are far more expensive than their counterparts cut from synthetic sapphire. Trying to figure out if you have an authentic star sapphire stone in your hands is quite difficult and that’s the problem!

You want to get a real star sapphire when making a purchase because the stone itself costs an arm and a leg. In this case, you might want to go through the descriptions carefully and skim through customer reviews to have a rough idea of what to expect from the company you’re considering purchasing from.

Getting a legit and reliable retailer online is even harder when hunting for natural sapphire stones with asterism. This is because, for the most part, fine jewelry retailers present their clients faceted sapphire rings.

An average buyer can barely tell the difference between a natural star sapphire and a synthetic star sapphire. This is because they are of the same quality and also have similar physical attributes. However, you can create the star in the gemstone.

Blue star sapphire stones with intense blue hues and six rayed star are probably fakes. Some fake star sapphires have a glass filling that can not only produce fake sapphires but also fake rubies with faceted cuts.

Star sapphire gemstones can cost quite a bit depending on the carat weight and color among others.

Treated Star Sapphire Stones

Even after treatment, a star sapphire ring is still a genuine sapphire ring. Words like lab grown, synthetic, processed and natural tend to throw people off. However, it’s not their fault. It took me a while to process it as well.

You’ll still find some of these words used extensively in the jewelry industry although its being phased out in favor of lab-created as opposed to synthetic materials.

Heat treatment is frequently used to change the color of star sapphire and faceted sapphire from light to medium or to improve clarity. Occasionally both. Heat treatment and other different gemstone treatments are often accepted as norms as they have little to no impact on the price and value.

However, there are certain treatments and gemstones that aren’t permanent but usually help enhance the quality of the stone. Such gems bring value and price in equal measure. For the most part, you’ll have to re-apply these treatments at an extra cost.

The simplest way to tell whether or not the gemstone has been treated is to go for star sapphires with certificates or grading reports. The grading report lets you know if the stone is natural or it has been subjected to any kind of treatment. These reports explain the different shades, treatments and clarity.

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It is incredibly difficult to tell the difference between treated and untreated star sapphire. When it comes to sapphire jewelry pieces, only the most qualified gem professionals could tell.

Are Star Sapphire Stones Best Suited for Engagement Rings?

Faceted sapphire stones make great engagement rings since they’re one of the most durable colored gemstones. Star sapphires, on the other hand, are more prone to damage but have the same durability. After many years of use, en cabochon cut gemstones are still susceptible to scratch owing to their rounded shape.

You might also want to consider the size of the gemstone. Not everyone would love a large stone on their engagement ring, even if some of the best star sapphire stones come in bigger carat weights.

Cabochons are quite bulky, so you can make them even bigger when you add more carats. It can be too loud or too heavy for some people’s taste.

Final Thoughts

Star sapphire crystals are usually as a result of a phenomenon in gemstones known as asterism. Sapphire stones are the most popular even tough other gemstones can also exhibit asterism. Blue sapphires, that is.

Blue is the most sought-after color when it comes to star gemstones. However, that doesn’t necessarily mean that other gemstones can’t exhibit asterism. You can subject star sapphire to heat treatment for clarity or to enhance its color.

In addition, star sapphire stones can also be lab created or filled with glass to pass off as an imitation of star sapphire. Always go for a star sapphire with a grading report or certificate to ensure you have a genuine one.

There are a few factors you need to put into consideration when choosing a star sapphire stone. The three main ones include carat weight, light performance and clarity. The rayed star should have distinct points without any distracting blotches and also be well centered.

Star sapphires with prominent stars in larger carat sizes can be valuable and extremely rare. These crystals are not best suited for engagement rings although they make beautiful pendants, earrings and cocktail rings.

Star sapphires are phenomenon gemstones. They’re ideal for those looking for unique gemstone designs out of the ordinary.

That’s it about star sapphire gemstones. Happy Shopping!

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