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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
Star Gemstones Clarity
Star Gemstones Price

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Black Star Gemstones
Blue Star Gemstones
Brown Star Gemstones
Golden Star Gemstones
Gray Star Gemstones
Green
Multicolor
Orange Star Gemstones
Pink Star Gemstones
Purple Star Gemstones
Red Star Gemstones
Turquoise
Violet
White
Yellow Star Gemstones
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Lots
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1.89ct Deep Blue Star Sapphire, Oval, Opaque

8 x 6 mm (calibrated)

$ 52.16

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1.23ct Deep Blue Star Sapphire, Oval, Opaque

6.9 x 4.6 mm

$ 48.71

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3.50ct Black Star Sapphire, Oval, Opaque

9 x 7 mm (calibrated)

$ 63.00

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13.87ct Medium-Dark Purple Star Ruby, Oval, Opaque

15.4 x 12.9 mm

$ 219.70

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64.50ct Mahogany Red Star Garnet, Oval, Opaque

27.2 x 22.4 mm

$ 76.63

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73.16ct Dark Red Star Garnet, Round, Opaque

23.3 mm

$ 289.72

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1.65ct Deep Blue Star Sapphire, Oval, Opaque

7.2 x 5.3 mm

$ 45.54

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5.51ct Black Star Diopside, Oval, Opaque

11 x 9 mm (calibrated)

$ 33.06

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14.27ct Dark Red Star Garnet, Oval, Opaque

16 x 12 mm (calibrated)

$ 16.96

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5.88ct Black Star Diopside, Oval, Opaque

11 x 9 mm (calibrated)

$ 35.28

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1.39ct Deep Blue Star Sapphire, Oval, Opaque

7 x 5 mm (calibrated)

$ 38.36

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11.48ct Reddish Purple Star Ruby, Oval, Opaque

14.1 x 11.4 mm

$ 181.85

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11.04ct Cantaloupe Orange Star Moonstone, Oval, Translucent

17.6 x 10.3 mm

$ 58.30

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3.46ctw Dark Blue Star Sapphire, Oval, Opaque

7 x 5.2 mm

$ 95.50

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5.89ct Grayish Magenta Star Ruby, Oval, Opaque

12 x 10 mm (calibrated)

$ 93.30

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38.00ct Mahogany Red Star Garnet, Oval, Opaque

20 x 15 mm (calibrated)

$ 45.14

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23.70ct Plum Purple Star Ruby, Oval, Opaque

17.5 x 15.2 mm

$ 375.41

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3.86ctw Deep Blue Star Sapphire, Oval, Opaque

7 x 5 mm (calibrated)

$ 91.72

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1.95ct Navy Blue Star Sapphire, Oval, Opaque

8 x 6 mm (calibrated)

$ 53.82

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3.46ct Black Star Diopside, Round, Opaque

9 mm (calibrated)

$ 20.76

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3.77ct Deep Red Star Ruby, Oval, Opaque

10 x 7 mm (calibrated)

$ 72.38

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5.15ct Medium Red Star Ruby, Oval, Opaque

10 x 8.5 mm

$ 98.88

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66.95ct Dark Purple Star Garnet, Oval, Opaque

21.8 x 18.6 mm

$ 441.88

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2.47ct Black Star Sapphire, Oval, Opaque

8.8 x 6.5 mm

$ 53.35

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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 -> 9 star ratings

It was great!

Posted By Annie in September, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

I was looking for a site with every type of gem I could want for setting in luxury blades and assumed I would need to look outside the US, but GemSelect made it easy to get everything I wanted without leaving the house! Wide enough selection that I do not feel the need to look elsewhere and pricing the same.

Posted By Razormane in April, 2025
Source: Bizrate

Overall Rating -> 9 star ratings

I love the gems!

Posted By MM in April, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

All items were delivered on time with all items meeting or exceeding my expectations. Cut, clarity and color were very close to the photos and description.

Posted By Bob D in December, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

Very food

Posted By Keeto in July, 2025
Source: Bizrate

Overall Rating -> 9 star ratings

I did not realize these stones were of jewelry quality. They are really beautiful, just not what I was expecting which was more of a natural stone.

Posted By Jewelry Quality Stones in July, 2025
Source: Bizrate
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