This time we are again introducing a more obscure yet no less interesting feldspar gemstone, the alluring andesine!

History and Meaning

The name andesine is derived from Andes (the mountain range in South America), where it is commonly found in the lava. Though the first description of andesine came from the Marmato mine in Colombia. There aren’t many legends or myths about andesine, unlike the other more well-known feldspar gemstones.  

Colours 

Andesine comes in a range of colours, namely white, gray, green, yellow and red. Though, it most commonly appears as a red gemstone and can be both transparent and translucent.

Andesine gem (https://geologylearn.blogspot.com/2016/11/andesine-gemstone.html)

Properties 

Andesine has a hardness between 6.0 – 6.5. Its composition of calcium and sodium can range from 50-50 to 30-70. It can also be fluorescent under UV light, glowing slightly orange or red depending on the wavelength of UV light. Like other feldspars, it can undergo weathering to form clay minerals and is often found as part of the soil. 

Location

Other than being found at its namesake, it can be found in the USA, parts of Europe like France, Germany and Italy, and even parts of Asia like India and Japan. They are common in igneous rocks with a moderate level of silica. 

Not So Fun Fact

In the 2000s, some low priced, red and green “andesine” gemstones appeared in the market. They destabilised the demand for Oregon sunstones (another type of feldspar gemstone) much to the chagrin of their miners. Eventually, it was found that these “andesine” were actually pale feldspars artificially injected with copper to achieve the sunstone’s aventurescent sparkle. The consequences of this issue were far reaching. Public trust towards natural Oregon sunstones was damaged the most, though andesine did also suffer a big blow to its reputation. 

On the brighter side, natural red andesine from a TIbetan source was verified after this controversy.