Tumblestones (also written 'tumble stones') are a form of crystals, minerals, and gemstones that is very popular with collectors and mineral enthusiasts. They are formed from natural rocks and minerals by a polishing process referred to as "tumbling", hence the name "tumble stones". During this process several, often very many, stones 'tumble' (fall) over each other while being rotated in a drum-like device. Over time this smoothes the edges of all the stones, some or all of which might have been rough initially. The process can be compared with the way in which some river stones or stones in the sea are smoothed by constant movement caused by the tide of river-flow among sand and other similar stones. When the process occurs naturally there is no way of knowing how long any particular stone has been 'tumbled' to achieve its polished-looking surface but it is likely to have been many years. When such processes are deployed in human-controlled environments, substances such as the ideal grade of grit are used to polish the stones as quickly as possible but even then it many take many weeks to achieve a good finish.
Considering the time and in some cases the machinery involved, tumblestones are usually extremely inexpensive to buy and collect. An interest in collecting gemstones in general and/or tumble stones in particular can begin early in life, with many interested and informed collectors still in Primary (Elementary) School.
See also the main IvyRose Holistic section about Crystals & Gemstones.