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Natural Star Gemstones

Discover rare star gemstones displaying the fascinating star effect known as asterism, perfect for collectors and unique jewelry designs.

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5.48ctw Blue Star Sapphire, Oval, Opaque

7 x 5 mm (calibrated)

$ 120.08

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2.86ctw Blue Star Sapphire, Oval, Opaque

7 x 5 mm (calibrated)

$ 62.67

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68.19ct Red Star Garnet, Oval, Opaque

24.4 x 21.4 mm

$ 56.03

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30.19ct Yellow Star Sapphire, Oval, Opaque

19.8 x 17.4 mm

$ 297.69

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4.93ct Brown Star Moonstone, Oval, Translucent

12 x 8.4 mm

$ 21.60

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4.23ct Black Star Sapphire, Oval, Opaque

10.4 x 7.6 mm

$ 75.84

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7.19ct Purple Star Ruby, Oval, Opaque

12.2 x 10.6 mm

$ 94.53

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6.89ct Purple Star Ruby, Oval, Opaque

12 x 10 mm (calibrated)

$ 90.59

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4.58ctw Blue Star Sapphire, Oval, Opaque

7 x 5 mm (calibrated)

$ 90.32

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13.92ct Brown Star Sunstone, Oval, Opaque

15.9 x 13 mm

$ 115.54

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5.00ct Black Star Diopside, Oval, Opaque

11 x 9 mm (calibrated)

$ 24.90

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10.38ct Yellow Star Moonstone, Oval, Translucent

16.2 x 14.1 mm

$ 45.48

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5.35ct Gray Star Sapphire, Oval, Opaque

9.5 x 9.1 mm

$ 186.50

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4.41ct Red Star Ruby, Oval, Opaque

9.5 x 8.2 mm

$ 70.28

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8.39ct Brown Star Moonstone, Oval, Translucent

12.8 x 10.1 mm

$ 27.58

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14.23ct Red Star Garnet, Oval, Opaque

11.3 x 11.6 mm

$ 14.74

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11.38ctw Black Star Diopside, Oval, Opaque

11 x 9 mm (calibrated)

$ 56.67

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6.34ctw Blue Star Sapphire, Oval, Opaque

7 x 5 mm (calibrated)

$ 138.93

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5.40ct Black Star Sapphire, Oval, Opaque

10 x 8 mm (calibrated)

$ 96.81

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4.48ct Purple Star Ruby, Oval, Translucent

10.4 x 8.8 mm

$ 58.91

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29.51ct Yellow Star Sapphire, Oval, Opaque

19.5 x 16.6 mm

$ 264.53

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4.26ct Black Star Sapphire, Oval, Opaque

10.7 x 8.3 mm

$ 63.64

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6.28ct Purple Star Ruby, Oval, Opaque

10.2 x 8.7 mm

$ 290.02

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4.63ct Black Star Sapphire, Oval, Opaque

10.2 x 8.5 mm

$ 83.01

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Why Buy Star Gemstones from GemSelect?

Natural Star Gemstones

Our natural star gemstones display the rare optical phenomenon known as asterism, where a star-shaped reflection appears across the gem’s surface. These unique stones are prized by collectors and jewelers for their striking appearance and rarity.

Star Gemstones Online

Buy star gemstones online at GemSelect with confidence. Our collection includes star sapphire, star ruby, and other rare gems with visible star effects, all available as loose stones ready for custom jewelry.

Loose Star Gemstones with Asterism

The Unique Star Effect (Asterism)

The star seen in these gemstones is caused by tiny needle-like inclusions that reflect light in a star-shaped pattern. This optical phenomenon, called asterism, becomes visible when the gemstone is cut as a smooth cabochon.

Star Sapphire Gemstones

Star sapphire is the most famous star gemstone, often displaying a clear six-rayed star across its surface. These gems are durable and popular for rings, pendants, and collector pieces.

Star Ruby Gemstones

Star rubies are rare and highly valued. When illuminated, they reveal a sharp star pattern over their deep red body color, making them one of the most sought-after asterism gemstones.

Cabochon Cut Star Stones

Star gemstones are typically cut as cabochons rather than faceted stones. The smooth, domed surface allows the star effect to appear clearly when the gem is viewed under direct light.

Loose Star Gemstones for Jewelry

Loose star gemstones are perfect for custom jewelry designs. Their distinctive optical effect makes them ideal for rings, pendants, and statement pieces that stand out from traditional faceted gems.

Collectible Star Gemstones

Many collectors seek star gemstones due to their rarity and unusual appearance. High-quality stones with centered and well-defined stars are especially desirable among gem enthusiasts.

Learn more about the properties and fascinating optical effects of gemstones on our Gemstone Optical Effects Guide.

FAQs

What are star gemstones?

Star gemstones are gems that display a star-shaped reflection on their surface. This optical phenomenon is called asterism and is most commonly seen in star sapphire and star ruby.

What causes the star effect in gemstones?

The star effect is caused by microscopic needle-like inclusions inside the gem that reflect light in intersecting lines, creating a visible star pattern when viewed under direct light.

Which gemstones show a star effect?

The most well-known star gemstones are star sapphire and star ruby, but asterism can also appear in gems like star garnet, star diopside, and occasionally in quartz.

Why are star gemstones cut as cabochons?

The cabochon cut allows the star pattern to appear clearly on the gem’s surface. Faceting would disrupt the optical effect and prevent the star from forming.

How can you see the star in a gemstone?

The star becomes visible when light hits the surface of the gemstone. Rotating the stone under a light source will make the star move across the surface.

GemSelect Certified Store Reviews

GemSelect: Over 22 Years in the Gemstone Business! Thank you for trusting us with your purchase!

Overall Rating -> 10 star ratings

The site provided lots of detail, factual data, and good photos. I also like the availability of searching by price range as well as by the type of stone.

Posted By SLIntuitive Donna in July, 2025
Source: Bizrate

Overall Rating -> 8 star ratings

Good prices

Posted By TRM in October, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

Had a great experience and the prices are great

Posted By BuBx99 in November, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

On the clarity options it goes "and better" so if youre looking for si specifically and you click si and better it still shows you basically everything. It just removes the opaques. Itd be nice if it was vs only, vss only, si only, etc

Posted By Iamnotakrustykrab in December, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

Very good place to buy gemstones

Posted By Elansary in March, 2026
Source: Bizrate

Overall Rating -> 10 star ratings

Filters need to be improved but rest of website is great

Posted By Rock hound in December, 2025
Source: Bizrate
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