Brazilian alexandrite is one of the rarest and most valuable varieties of the mineral chrysoberyl, prized for its unique color-changing properties. This gemstone was first discovered in the Ural Mountains of Russia in 1830 and was named after Tsar Alexander II. However, it wasn't until the late 1800s that alexandrite was discovered in Brazil, where some of the finest specimens have been found.

One of the most distinctive features of Brazilian alexandrite is its ability to change color under different lighting conditions. In natural daylight or fluorescent light, it appears green to bluish-green, while in incandescent light it can appear reddish-purple or even pink. This phenomenon is caused by the presence of chromium, iron, and titanium in the crystal structure, which absorbs different wavelengths of light.

The rarity of Brazilian alexandrite is due to several factors. First, it is found in only a few locations in Brazil, including the states of Minas Gerais, Bahia, and Espirito Santo. Second, the mining of alexandrite is labor-intensive and requires skilled workers to extract the gemstones from the surrounding rock. Finally, the quality of Brazilian alexandrite is highly variable, with only a small percentage of the mined stones exhibiting the color-changing properties and clarity that make them valuable as gemstones.

Despite its rarity and high value, Brazilian alexandrite has a relatively short history in the world of gemstones. It wasn't until the late 1800s that it was first discovered in Brazil. As the supply of Russian alexandrite dwindled and the quality of Brazilian stones improved, Brazilian alexandrite began to gain recognition as a rare and valuable gemstone.

Brazilian alexandrite is a variety of the mineral chrysoberyl which is an aluminate of beryllium with the chemical formula BeAl2O4. It is beryllium aluminum oxide and has the same chemical composition as ordinary chrysoberyl with trace amounts of chromium giving the gemstone its characteristic color-changing properties. However, the specific chemical composition of Brazilian alexandrite may vary slightly depending on the location where it was mined. Overall, the chemical composition of Brazilian alexandrite is very similar to that of Russian alexandrite, and it is the presence of chromium in both gemstones that is responsible for their unique and highly prized color-changing properties.

Today, Brazilian alexandrite is highly sought after by collectors and gem enthusiasts, with prices ranging from a few thousand dollars to tens of thousands of dollars per carat depending on the quality of the stone. Its rarity and unique color-changing properties make it a prized addition to any gem collection, and its history and heritage add to its appeal as a truly exceptional gemstone.

Today even a 5-6 carat Brazilian Alexandrite is considered a rarity. Here are some of the most famous Brazilian Alexandrites from the past:

1. The Empress of Uruguay: This is a rare and exquisite Brazilian Alexandrite that weighs in at 66.24 carats. It is considered to be one of the finest examples of Alexandrite in the world and is owned by an anonymous private collector.

2. The Dom Pedro Alexandrite: This is a 13.74-carat Brazilian Alexandrite that is widely regarded as one of the world's most famous and valuable gemstones. It is named after Brazil's second emperor, Dom Pedro II, who was an avid collector of gems.

3. The Serra do Mar Alexandrite: This is a 121.65-carat Brazilian Alexandrite that is owned by an unknown private collector. It is a rare and unique gemstone that displays a distinct cat's eye effect.

4. The Diamantina Alexandrite: This is a 17.08-carat Brazilian Alexandrite that is known for its exceptional color change and clarity. It was discovered in the Diamantina region of Brazil and is currently owned by a private collector.

5. The Rio Doce Alexandrite: This is a 48.68-carat Brazilian Alexandrite that is known for its vibrant and intense color change. It was discovered in the Rio Doce region of Brazil and is currently owned by an unknown private collector.