Stromatolite Tumbled Gemstone - various sizes available

This mineral consists of layered accretionary structures formed in shallow water by the trapping binding and cementation of sedimentary grains by biofilms of microorganisms especially cyanobacteria (commonly known as blue-green algae). This can include some of the most ancient records of life on Earth. Featuring a mixture of round and flat polishing, these wonderful tumbles are available in three sizes:-

• Medium - 20mm by 25mm approximately
• Large - 30mm by 25mm approximately

Photo is to show natural variation, as one of these fine gems will be picked intuitively.