Brazilian Euclase

Brazilian Euclase hails from Santana do Encoberto (Santa do Encoberto) in the Brazilian state of Minas Gerais (English: General Mines) and is yet another captivating, rare exotic gem from one of the world’s premiere gemstone countries. With attractive pastel straw and buttery hues, excellent brilliance and a good durability, Brazilian Euclase’s extreme geological scarcity coupled with challenges for lapidaries, has unfortunately resulted in it being a relatively unknown gemstone, highly coveted by collectors.

Hardness 7.5
Refractive Index 1.650 – 1.676
Relative Density 2.99 – 3.13
Enhancement None


Displaying beautiful pastel straw to buttermilk yellows with an exceptional brilliance, Brazilian Euclase occasionally forms crystals with enough clarity to be faceted. While Brazilian Euclase’s color, brilliance and hardness makes it an ideal jewelry gemstone, its perfect cleavage (easily breaking into continuous flat surfaces) in one direction can be challenging for lapidaries. However, when a specimen possesses well-formed crystals with attractive colors, a skilled cutter can work Euclase to its own advantage, creating highly collectable and extremely beautiful exotic gemstones. Optimal lapidary accentuates the innate beauty of Brazilian Euclase and every gem is finished eye-clean, the highest quality clarity grade for colored gemstones as determined by the world’s leading gemological laboratories, with an attractive shape and overall appearance.

Euclase is a transparent to translucent beryllium aluminum hydroxide silicate mineral coming in colorless, dark blue, pastel blue, pastel green, violet, white, and yellow. Euclase was likely first discovered in South America and sent to Europe in 1785, with its first European occurrence reported in 1792 at the gold-bearing gravels of the Sakmara River in the Orenburg district of Russia’s southern Urals, where it is found with Chrysoberyl and Topaz. It was named by French crystallographer and mineralogist, René Just Haüy (1743–1822) from the Greek Eu (εὖ), easily, and Klasis (κλάσις), fracture, in reference to its perfect cleavage. Interestingly, the gemstone Haüyne, or Haüynite, was named in 1807 by Brunn-Neergard for René. A granite pegmatite (a coarsely crystalline igneous rock) mineral, Euclase that has been weathered from its host rock can also be found in alluvial gold deposits.


While Euclase gemstones are occasionally mined in Kenya, Zimbabwe, Tanzania, Russia, and Colombia, Brazil, notably deposits at Ouro Preto and Santana do Encoberto in the Brazilian state of Minas Gerais, is the premier source. Our Brazilian Euclase was mined at Santana do Encoberto in the municipality São Sebastião do Maranhãov in the 1990’s. Most Brazilian Euclase is old mine production and in the past few years, these scant reserves have become increasingly difficult to obtain. Most Brazilian Euclase crystals occur in small sizes, usually under 3 carats, and it is also one of the few gemstones that are totally natural and unenhanced.

Durability & Care

A durable jewelry gemstone, Brazilian Euclase (Mohs’ Hardness: 7.5) should always be stored carefully to avoid scuffs and scratches. Clean with gentle soap and lukewarm water, scrubbing behind the gem with a very soft toothbrush as necessary. After cleaning, pat dry with a soft towel or chamois cloth.

Map Location

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