Aventurine Properties, Facts and Photos
What is Aventurine?
Aventurine is a quartz-based rock with minute inclusions of other minerals. The inclusions are often described as 'platy' in reference to their plate-like shape. They usually have a flaky appearance.
Mineral inclusions described as 'platy' are mostly lepidolite mica, fuchsite (fook-site), goethite (ger-tight) or hematite.
A glistening or spangled effect, known as aventurescence, can be seen as light reflects off these minute mineral inclusions.
Fuchsite causes aventurine to become green. Hematite, goethite (ger-tight), and lepidolite mica produce shades of pink, purple, orange, red and brown.
The colour of blue aventurine is believed to come from dumortierite and/or copper. Shades of grey and some shades of yellow come from muscovite or ilmenite.
Aventurine is believed to have been named after the man-made material called goldstone. Like aventurine, goldstone exhibits aventurescence.
Impurities in a rock or mineral can influence its colour. The intensity or extent of the colour-change can vary depending on the concentration of the impurity.
The more common orange-brown goldstone is produced using colourless glass. The stone's colour comes from inclusions of crystallised copper.
Most of the world's blue and green aventurine comes from India. Off-white, grey and yellowish-orange stones can be found in Chile, Spain and Russia. Aventurine in other colours is found in Brazil, Austria and Tanzania.
Although often referred to as a mineral, aventurine is a rock. It's a quartzite, which is a metamorphic rock that started as sandstone.
During the Stone Age, primitive tools were made of quartzite when flint was not available. Although not as easy to work with, quartzite is hard yet brittle, which makes it relatively easy to shape.
Aventurine, also known as aventurine quartz, grades 6.5 to 7 on the Mohs scale of hardness.
Many articles online report aventurine was discovered by J.D. Dan in 1837, however, I can find nothing factual to support this.
J.D. Dan is likely to be James Dwight Dana [1813 - 1895], an American geologist, mineralogist, volcanologist, and zoologist. Although he wrote about aventurine and sunstone, there is no evidence to suggest that he discovered either mineral.
Article Pictures
The rough green aventurine in the photo at the top of our article and the orange aventurine tumbled stones are from our collection.
The second piece of green aventurine is displayed in London's Natural History Museum. Photo by Stone Mania.
Images are clickable and redirect to the original photo.
Pop-up images: The goldstone and sunstone are from our collection. Hematite and muscovite - Courtesy of Stan Celestian.
Fuchsite - Courtesy of James St. John. Ilmenite - Courtesy of Ron Wolf.
