Cobaltoan calcite crystals tumbled from stone mined in the Democratic Republic of Congo. Large and distinctively pink, these beautiful grade A stones deserve to be displayed somewhere they can be seen and enjoyed.
Their impressive colour is caused by impurities of cobalt. This relatively rare mineral can be found in just a few countries around the world. Most of the finest specimens come from Congo and Morocco.
Cobalt is one of the most economically important metals in the world. It's a vital component for the production of lithium ion batteries which are rechargeable batteries used in electronic equipment and various applications.
When a higher concentration of cobalt is present the shade and depth of colour is increased.
We are unable to confirm whether the pink colour of cobaltoan calcite is stable. Exposure to sunlight can damage the colour of many minerals, fluorite and amethyst being a perfect example. We therefore do not recommend these tumbled stones be placed close to a window or outside in natural daylight.
Although classed as a large stone, weights and sizes of these cobaltoan calcite tumbled stones does vary slightly from piece to piece.