90,000+Happy Customers
20+Years
WorldwideShipping
Cart
Free Report Included
Worldwide Shipping
30 Day Returns
Help Center Shipping Payment and Checkout Returns Certificates Contact Us
Home Gemstones Star Gemstones

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

Size Explained

Choose Size or Size Range
For Example: 6-7
For Example: 8-9
Bi-color
Black Star Gemstones
Blue Star Gemstones
Brown Star Gemstones
Golden
Gray Star Gemstones
Green
Multicolor
Orange Star Gemstones
Pink Star Gemstones
Purple Star Gemstones
Red Star Gemstones
Turquoise
Violet
White
Yellow Star Gemstones
Single
Pairs
Lots
Faceted
Cabochons
X
Clear All

4.75ct Purple Star Ruby, Oval, Opaque

9.7 x 7.5 mm

$ 219.36

View Gem

1.38ct Black Star Diopside, Oval, Opaque

8 x 6 mm (calibrated)

$ 6.87

View Gem

7.64ct Black Star Sapphire, Oval, Opaque

12 x 10 mm (calibrated)

$ 152.19

View Gem

7.59ct Black Star Diopside, Oval, Opaque

12 x 10 mm (calibrated)

$ 37.80

View Gem

12.28ct Purple Star Ruby, Oval, Opaque

15.3 x 12.6 mm

$ 161.45

View Gem

36.43ct Yellow Star Sapphire, Oval, Opaque

20.6 x 17.6 mm

$ 359.22

View Gem

2.08ct Black Star Diopside, Oval, Opaque

8 x 6 mm (calibrated)

$ 10.36

View Gem

1.95ct Blue Star Sapphire, Oval, Opaque

8 x 6 mm (calibrated)

$ 44.67

View Gem

4.91ct Black Star Sapphire, Oval, Opaque

9.8 x 7.5 mm

$ 88.03

View Gem

5.27ct Black Star Diopside, Oval, Opaque

11 x 9 mm (calibrated)

$ 21.87

View Gem

4.56ct Purple Star Ruby, Oval, Opaque

10.9 x 8.3 mm

$ 59.95

View Gem

6.14ct Red Star Ruby, Oval, Opaque

11.8 x 8.9 mm

$ 94.18

View Gem

4.00ct Black Star Sapphire, Oval, Opaque

10.5 x 8.2 mm

$ 71.71

View Gem

3.75ctw Blue Star Sapphire, Oval, Opaque

7 x 5 mm (calibrated)

$ 73.95

View Gem

1.85ct Black Star Diopside, Oval, Opaque

8 x 6 mm (calibrated)

$ 9.21

View Gem

5.88ct Black Star Diopside, Oval, Opaque

11 x 9 mm (calibrated)

$ 29.28

View Gem

6.11ct Black Star Diopside, Oval, Opaque

12 x 10 mm (calibrated)

$ 30.43

View Gem

6.93ct Purple Star Ruby, Oval, Opaque

12 x 10 mm (calibrated)

$ 91.12

View Gem

3.01ctw Blue Star Sapphire, Oval, Opaque

7 x 5 mm (calibrated)

$ 65.95

View Gem

26.49ct Red Star Garnet, Round, Opaque

16 mm (calibrated)

$ 26.13

View Gem

11.47ct Purple Star Ruby, Oval, Opaque

12.5 x 11.3 mm

$ 150.79

View Gem

4.27ct Purple Star Ruby, Oval, Opaque

10.8 x 7.6 mm

$ 197.19

View Gem

21.47ct Yellow Star Sapphire, Oval, Opaque

16.6 x 13.8 mm

$ 192.46

View Gem

28.69ct Red Star Garnet, Oval, Opaque

20 x 11.7 mm

$ 29.72

View Gem

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

Great website, easy to navigate, and loads quickly. Have bought here before, very pleased!

Posted By SallyO in February, 2026
Source: Bizrate

Overall Rating -> 10 star ratings

Easy process.

Posted By Crafty Seabee in March, 2026
Source: Bizrate

Overall Rating -> 9 star ratings

Will know more once order received

Posted By Jim in September, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

Very good

Posted By Niska in August, 2025
Source: Bizrate

Overall Rating -> 10 star ratings

Wonderful purchase, can't wait to see the stone.

Posted By Tim in January, 2026
Source: Bizrate

Overall Rating -> 10 star ratings

I was looking for high-quality amethyst on this site, and I was able to compare size, color, and weight in detail before making a purchase.

Posted By Atsuhisa in January, 2026
Source: Bizrate
Enlarged Gemstone Image