Filamentose Carbonate of Lime

The specimen here figured is part of the cliff that lately fell down at Brighton. It was rightly considered by the generality of observers to be Pebble Stones cemented by Spar, and was brought me by the Rev. J. T. Barret. The largeness of the spaces for the cementing Carbonate of Lime is such that it crystallizes and 1ms a remarkable appearance, and is a novelty to most mineralogists of the present day. Besides this, there is in some marly parts a substance which has nearly the appearance of the remains of Shells, that is remarkable for its filamentose form and satiny lustre: sometimes this is in contact with the usually crystallized Carbonate of Lime, and occasionally much resembles the Asbestos found in the Serpentine rocks of North Wales and some parts of Scotland. It is extremely tender, and, when white, appears to be very pure Carbonate of Lime. The colouring substance in some giving rather a crimson hue, may indicate Oxide of Iron with a trifle of Manganese. The filaments easily crumble, therefore the little flexibility is but difficultly discernible. The substance is often placed in three or more layers above each other. The silky or satiny lustre soon distinguishes it when turned to the light. It perhaps is not only a new appearance, but, as in a mass of two or three hundred weight very little was to be found, it seems to be rather rare.