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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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1.59ct Black Star Diopside, Oval, Opaque

8 x 6 mm (calibrated)

$ 7.92

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6.24ct Purple Star Ruby, Oval, Opaque

10.8 x 9.6 mm

$ 82.04

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5.27ct Black Star Diopside, Oval, Opaque

11 x 9 mm (calibrated)

$ 21.87

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4.44ct Black Star Diopside, Oval, Opaque

11 x 9 mm (calibrated)

$ 18.43

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4.26ct Purple Star Ruby, Oval, Opaque

10.7 x 8 mm

$ 196.73

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5.59ct Black Star Sapphire, Oval, Opaque

11.2 x 8.5 mm

$ 111.35

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15.14ct Purple Star Ruby, Oval, Opaque

14 x 12 mm (calibrated)

$ 199.05

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3.25ct Black Star Sapphire, Oval, Opaque

10.6 x 8 mm

$ 48.56

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3.21ctw Blue Star Sapphire, Oval, Opaque

7.3 x 5.3 mm

$ 73.54

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17.03ct Purple Star Ruby, Oval, Opaque

16.2 x 13.4 mm

$ 223.90

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9.87ct Red Star Garnet, Oval, Opaque

13.1 x 10.4 mm

$ 9.73

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4.71ctw Blue Star Sapphire, Oval, Opaque

7 x 5 mm (calibrated)

$ 92.89

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12.54ct Purple Star Ruby, Oval, Opaque

14 x 12 mm (calibrated)

$ 164.87

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8.75ct Black Star Sapphire, Oval, Opaque

12 x 10 mm (calibrated)

$ 174.30

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2.36ct Black Star Sapphire, Oval, Opaque

9 x 7 mm (calibrated)

$ 42.31

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24.49ct Purple Star Ruby, Oval, Opaque

16.5 x 15 mm

$ 321.97

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37.26ct Yellow Star Sapphire, Oval, Opaque

19.6 x 16.9 mm

$ 367.39

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3.95ct Black Star Sapphire, Oval, Opaque

10 x 8 mm (calibrated)

$ 70.82

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5.24ct Black Star Sapphire, Oval, Opaque

10.6 x 8.4 mm

$ 77.84

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21.47ct Yellow Star Sapphire, Oval, Opaque

16.6 x 13.8 mm

$ 192.46

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5.78ct Purple Star Ruby, Oval, Opaque

9.3 x 8.2 mm

$ 69.08

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77.87ct Red Star Garnet, Oval, Opaque

25.4 x 23.1 mm

$ 76.78

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3.91ctw Blue Star Sapphire, Oval, Opaque

6.9 x 5.2 mm

$ 77.11

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28.69ct Yellow Star Sapphire, Oval, Opaque

18.2 x 15.4 mm

$ 282.90

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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

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Overall Rating -> 7 star ratings

Easy, quick.

Posted By Mich in June, 2026
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Overall Rating -> 10 star ratings

Found a rock that met my need. Bought it!

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

The website was very easy to use.

Posted By Garnet in January, 2026
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Overall Rating -> 10 star ratings

Web site is very simple to navigate Selection is terrific

Posted By ToRa.62 in April, 2026
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Overall Rating -> 10 star ratings

Loved the price and the quality and the certification options which is the main reason why I buy. The guarantee is also a great reason to use gem select.

Posted By Sal in July, 2025
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Overall Rating -> 10 star ratings

Very good.

Posted By Tommy in December, 2025
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