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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.

Star Gemstones Weight
Star Gemstones Size
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Black Star Gemstones
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Orange Star Gemstones
Pink Star Gemstones
Purple Star Gemstones
Red Star Gemstones
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3.89ct Black Star Sapphire, Oval, Opaque

10.9 x 8.6 mm

$ 93.36

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3.20ct Red Star Ruby, Oval, Opaque

9.7 x 7.6 mm

$ 178.05

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13.18ct Purple Star Ruby, Oval, Opaque

13.6 x 11.3 mm

$ 208.78

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2.76ct Blue Star Sapphire, Oval, Opaque

9 x 7 mm (calibrated)

$ 63.48

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9.31ct Purple Star Ruby, Oval, Opaque

13 x 11 mm (calibrated)

$ 147.47

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8.51ct Black Star Diopside, Round, Opaque

11 mm (calibrated)

$ 51.06

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3.12ct Red Star Ruby, Round, Opaque

8 mm (calibrated)

$ 59.90

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9.43ctw Black Star Diopside, Oval, Opaque

11 x 9 mm (calibrated)

$ 56.58

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12.00ctw Black Star Diopside, Oval, Opaque

11 x 9 mm (calibrated)

$ 60.00

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13.67ct Red Star Ruby, Oval, Opaque

14 x 12 mm (calibrated)

$ 216.53

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15.32ct Red Star Garnet, Oval, Opaque

17.2 x 10.6 mm

$ 19.12

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15.06ct Purple Star Ruby, Oval, Opaque

16.1 x 11.3 mm

$ 376.50

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6.83ct Black Star Sapphire, Oval, Opaque

11.7 x 9.4 mm

$ 163.92

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4.70ct Black Star Sapphire, Oval, Opaque

10.5 x 8.4 mm

$ 101.52

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21.16ct Red Star Garnet, Oval, Opaque

18 x 14 mm

$ 25.14

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11.26ct Black Star Diopside, Round, Opaque

12 mm (calibrated)

$ 67.56

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15.14ct Purple Star Ruby, Oval, Opaque

14 x 12 mm (calibrated)

$ 239.82

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5.18ctw Blue Star Sapphire, Oval, Opaque

7 x 5 mm (calibrated)

$ 123.07

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0.69ct Blue Star Sapphire, Oval, Opaque

5.3 x 4.1 mm

$ 27.60

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5.41ct Gray Star Sapphire, Oval, Translucent

9.5 x 8.3 mm

$ 189.35

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5.51ct Black Star Diopside, Oval, Opaque

11 x 9 mm (calibrated)

$ 33.06

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5.78ct Black Star Diopside, Oval, Opaque

11 x 9 mm (calibrated)

$ 34.68

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3.39ctw Blue Star Sapphire, Oval, Opaque

7 x 5 mm (calibrated)

$ 89.50

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4.05ct Black Star Sapphire, Oval, Opaque

9.6 x 7.1 mm

$ 87.48

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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 -> 8 star ratings

I've purchased things from GemSelect before. What you see is what you get, which is not always the case with gem sites online. You can find some good value with gem select, and I will buy from them again.

Posted By Meyeusername in March, 2026
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Overall Rating -> 10 star ratings

I have shopped at Gemselect for nearly 20 years. I especially like that you see pictures of the exact gem you are purchasing. You are a trusted source.

Posted By DNaber in October, 2025
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Good. I ts very user friendly.

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It was easy to navigate

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Overall Rating -> 10 star ratings

I had a very easy time navigating the web page and using filters to find what I was looking for. The varied selection was nice to see and pricing is clear and fair.

Posted By Mattick in May, 2026
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Overall Rating -> 10 star ratings

I was able to find what I wanted very easily!

Posted By Lenny in January, 2026
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