Sapphirine Gemstone: The Rare “Fake Sapphire” Explained

In the world of gemstones, beauty and mystery often go hand in hand — and so does the fear of accidentally taking home a fake. Even with some gemological knowledge, I still worry about misidentifying a stone. While I usually handle real sapphires, today we’re exploring their unexpected counterpart: the Sapphirine gemstone, often nicknamed the “fake sapphire.” And yes — it’s a real mineral.

0.56 carat clean and transparent Sapphirine gemstone showing bluish-green hues — A 0.56 carat clean and transparent Sapphirine gemstone (Fake Sapphire)

Before we begin, here’s a quick clarification.

Note: In this article, “fake sapphire” refers to the natural mineral Sapphirine — not lab-grown sapphire. These two are completely different things.

Why Is it Called “Fake Sapphire”?

Sapphirine crystal with brown mica and white calcite inclusions, showing natural texture and mineral composition — Sapphirine Crystal – Brown: Mica (Biotite) · White: Calcite

Sapphirine, often nicknamed “fake sapphire,” is a natural magnesium aluminum silicate discovered in 1819 in the Fiskenaesset (Fiskenæs) region of western Greenland. It belongs to the monoclinic crystal system and shows distinct cleavage.

Most sapphirine crystals appear as grainy aggregates, and transparent pieces suitable for faceting are extremely rare. That’s why clean, faceted sapphirine gemstones are highly sought after by collectors.

So why the nickname?
Because its body color often resembles that of blue sapphire — enough to fool the untrained eye.

Characteristics of Sapphirine gemstone (“Fake Sapphire”)

Rough Sapphirine gemstone with Mohs hardness of 7.5, demonstrating excellent durability and natural texture

Sapphirine crystal with brown mica and white calcite inclusions.

Hardness & Durability

Unlike many rare minerals that scratch at the slightest touch, sapphirine scores 7.5 on the Mohs scale, giving it impressive durability. This hardness makes it a favorite among collectors who appreciate rare gems that can actually withstand wear.

Color

Two Sapphirine gemstones on the same background, one bluish-green and the other with a strong gray undertone

Sapphirine almost always carries a noticeable gray undertone, a key visual clue. Its most common hues include:

Bluish-green
Greenish-blue
Occasional violet or other color variations

At first glance, it can look strikingly similar to sapphire — and on other occasions, it resembles Sri Lanka’s famous gray spinel, except without spinel’s lively fire.

For gemstone enthusiasts curious about spinel, check out our PeonyJewels blog article: The Legendary Hope Spinel and Hope Pearl: Rare Gems That Captivated the World, where we explore the fascinating history and unique characteristics of these iconic treasures.

Optical Properties

Triangular faceted Fake Sapphire with refractive index 1.701–1.718, showing bluish-green color and clarity

Refractive Index (RI): 1.701–1.718
Birefringence (DR): 0.005–0.006
Optic Character: Biaxial negative
Specific Gravity (SG): 3.51–3.56

These properties help gemologists distinguish it from sapphire, though the casual buyer wouldn’t spot these differences without proper equipment.

The Largest Known Faceted Sapphirine gemstone

According to current records, GIA identified the largest clean, faceted sapphirine, which weighs 1.72 carats.

The gemstone displays strong pleochroism, showing bluish-green and pale yellow tones from different viewing angles. Although it has an impressive size, its cut quality falls short — yet with rare gemstones, rarity often matters far more than perfection.

Where Does Sapphirine gemstone Come From?

Today, sapphirine mainly comes from three gemstone-rich regions:

Sri Lanka
Madagascar
Tanzania

All three countries produce an astonishing variety of gemstones, but even after spending a long period in Sri Lanka myself, I have rarely encountered high-quality faceted sapphirine.

So when I do come across one — and the price is fair — I don’t hesitate to add it to my collection.

Final Thoughts

Rare gemstones earn their title for a reason — sometimes because of limited mining areas, sometimes because of extremely low production. Many of them are so scarce that a collector may never encounter a fine specimen in their entire lifetime. And yes, some rare stones aren’t conventionally “pretty” and may not compete with crystal’s clarity and sparkle.

But that’s exactly the charm: not everyone gets to own them.
For true gemstone lovers, the joy lies in discovering, learning, and collecting every unique treasure nature creates.

Peonyjewels Says

If you enjoy exploring uncommon gems like sapphirine, you’ll love the craftsmanship behind our handmade vintage-style jewelry. At Peonyjewels, we offer:

Custom jewelry services
Handmade vintatge earrings and accessories inspired by historical and natural aesthetics

Whether you’re a collector or simply love meaningful, artisanal pieces, Peonyjewels brings rare-gem inspiration into wearable art.

Why Is it Called “Fake Sapphire”?