1998. By Grant Keddie INTRODUCTION They assume fantastic and complex forms. They look like an exotic fossil, an animal carved by an ancient artist or something from another planet. One of the most common items that arouse excitement in people, and which are brought frequently to Museums for identification, are sedimentary stone structures called concretions. They are widespread and found in a great variety of unusual shapes – that range in size from a garden pea to giant spheroidal balls three meters in diameter. The joining or inter-growth of several elongate or disc shaped concretions often produce a kind of symmetry which, to the untrained eye, suggests they must have been made by human hands. Concretions are natural objects which … Continue reading “Concretions”