Grandidierite is an extremely rare gemstone prized for its dark blue-green or dark green color. It is one of the rarest gemstones in the world due to its unique characteristics and properties. It can only be found in Madagascar and Sri Lanka, making it a highly prized possession by collectors and mineral enthusiasts alike.

Moreover, gem quality grandidierite stone’s rarity makes it highly sought after and valuable; with some specimens selling for tens of thousands of dollars. In this article, you will discover the history behind this rare gemstone and why it is considered a gem-quality material.

1What is Grandidierite?

Grandidierite is a recently discovered gemstone in 1902, originating from the southern region of Madagascar. The first samples in initial discovery were found by French mineralogist Alfred Lacroix, who named the crystal after French explorer Alfred Grandidier.

It was created from molten rock that surfaced from below the Earth’s crust. It is a silicate mineral formed over millions of years. The first discoveries of grandidierite stones were found in pegmatite outcrops on the Andrahomana cliffside of Madagascar. Other small batches of grandidierite stones have since been found in many other parts of the world, including, Malawi, Sri Lanka, Antarctica, Australia, and Namibia. However, most gem-quality grandidierite comes from southern Madagascar and Kolonne Sri Lanka which are extremely rare minerals.

Grandidierite has been in popular demand due to its rare and beautiful properties. Moreover, it is believed by the International Gem Society that grandidierite gemstones are rare minerals in transparent material compared to other gemstones because they are very difficult to find.

Also, the minimal supply of grandidierite faceted gemstones in eye-clean crystal form makes it an expensive gemstone.

2Identifying Grandidierite

Grandidierite gemstones have a unique composition with a distinct 7.5 on the Mohs scale. It is often distinguished by its parallel growth planes and characteristic bluish-green, greenish-blue, or brown coloration. This coloration can be attributed to the iron content present in these gem-quality crystals. For instance, the grandidierite appears bluer in color if it has more iron (Fe) content

Moreover, grandidierite crystals are one of the hardest-known minerals available making them ideal for use in jewelry. They display strong trichroic pleochroism, which means they can show three different colors depending on the viewing angle: dark blue-green, colorless (light yellow), or dark blue-green. For instance, the intensity of the blue saturation changes as light enters it from different angles reflecting off different blue hues. This characteristic is considered to be a rare feature of a gemstone and adds to its uniqueness.

So, if a gem cutter manages to keep as much of the weight of the stone as possible while showing off the pleochroism of the stone; that gem-quality grandidierite can be sold for significantly high prices. Fine quality grandidierite with the best possible cut, color, and clarity can fetch upwards of $20,000 per carat.

Grandidierite gems from Madagascar may have the following properties:

  • Refractive Index: a = 1.583, y =1.622

  • Specific Gravity: 2.85

The minimal supply of grandidierite has led to a low demand for grandidierite. This and the lack of knowledge in the gem industry have not allowed grandidierite to rise in popularity as much as diamonds or sapphires.

3Is Grandidierite natural?

Grandidierite is a rare gemstone that has been making waves in the gem and jewelry industry. However, its rarity has also made it a target for treatments and enhancements, which raises questions about its authenticity. So, is Grandidierite a natural gemstone?

The answer is yes! Grandidierite is an unheated, untreated natural gemstone. It is known that around 90% of gemstones in the gem market are enhanced using processes such as heating at extremely high temperatures to improve their color, or oiling the gemstones to improve their clarity and color.

However, unlike other gemstones, grandidierite does not require any treatment to look stunning. They look beautiful in their true form which adds a factor to why grandidierite gemstones are rare and expensive.

4Grandidierite Price & Value

Grandidierite, a rare and unique gemstone, has been capturing the fascination of gem enthusiasts worldwide. With its mesmerizing blue green colors and remarkable clarity, this precious stone commands an expensive price per carat that reflects its exceptional rarity. At present, the estimated price for grandidierite ranges from $8,000 to $20,000 per carat – making it one of the most costly rare mineral on the market. But some of the light blue or light blue green colored gemstones may have a lower price ranging from $500 to $3,000 per carat.

The value of grandidierite lies not only in its scarcity but also in its breathtaking beauty that sets it apart from other gems. Its unique combination of color and crystal clarity makes it highly sought after by collectors and connoisseurs alike. This exquisite gem’s enduring appeal underscores its status as a cherished investment piece with a timeless allure. As demand for rare gemstones continues to grow, the allure and value of grandidierite are poised to ascend even further into enviable heights within the realm of fine jewelry and gemstone investments.

Usually, grandidierite gemstones are commonly mistaken for Blue Topaz, Blue Apatite or even paraiba tourmaline which are of similar color and look, but the rarity of grandidierite mineral is far superior to these 2 gemstones. Likewise, mineral specimens of grandidierite in eye clean crystals also fetch very good prices depending on the crystal formations and gem quality stones cannot be usually cut from these mineral specimens due to phase inclusions that are commonly seen.

5Grandidierite Jewelry

The intense color and luster of grandidierite faceted gemstones make it an ideal choice for use in jewelry. They are known for their unique combination of colors, ranging from electric blues to vibrant greens.

6Grandidierite Care

Handling grandidierite gem quality stones requires a delicate touch, as this rare gemstone is relatively soft compared to other precious stones. It measures 7 to 7.5 on the Mohs scale, making it susceptible to scratches and chipping if not handled with care. When cleaning grandidierite jewelry, avoid using harsh chemicals or ultrasonic cleaners that could damage the stone’s surface. Instead, gently wipe the gem with a soft, damp cloth and mild soap before rinsing thoroughly and patting dry.

Storing grandidierite separately from other jewelry can prevent scratching or abrasions. Consider wrapping the stone in a soft cloth or placing it in a fabric-lined jewelry box to protect its delicate surface. Additionally, periodic inspections by a professional jeweler can ensure that any potential issues are addressed promptly, preserving the integrity and beauty of this remarkable gemstone for years to come.