Calcareous soils exist in many different forms, each possessing unique characteristics. This paper deals with a 100m deep calcareous soil deposit consisting of over 60% aragonite, an orthorhombic-shaped crystalline form of calcium carbonate. Undisturbed push-tube samples of the soil show void ratios generally greater than about 1.7, even to depths of 100 m. When the samples are reconstituted by sedimentation and reconsolidation, the highest void ratio that can be achieved is about 1.3 at equivalent effective stress levels. A technique for achieving higher void ratios is described. This involves sedimenting the soil in water containing a synthetic flocculant - Magnafloc Mg 919, from Allied Colloids (Australia) Pty Ltd. The resulting samples have void ratios equivalent to those of the undisturbed samples at corresponding effective stress levels. However, additional 'curing' of the samples, using heat treatment, was found to be necessary to achieve the same monotonic and cyclic shear behaviour as that of the undisturbed soil. The paper also includes an examination of the microstructure of the natural and reconstituted samples, carried out using an environmental scanning electron microscope.