Sandstone Description: Sandstone is a type of sedimentary rock formed of gritty sand grains and is available in a variety of colours. Sandstone paving is available in a range of different textures, often relying on secondary processing to achieve these finishes. Handcut Riven Sandstone This type of sandstone has a rough, uneven surface texture with occasional ridges and the edges of the slabs are usually tapered with the larger face of the slab to be laid uppermost. This sandstone may be of random thickness, usually ranging between 25-40mm. Some variable thickness paving may be nearer 15-22mm thick which is often priced lower. Although thinner, this paving is perfectly suited to use in the UK when laid on a full mortar bed which provides the paving with additional strength. Some riven sandstone products are offered at a 'calibrated' thickness which means the paving has been cut to a less variable, relatively even depth, usually around 22mm +/-, to make it easier to lay. This reduced thickness does not affect the quality. There are many colour choices available with the handcut riven style of sandstone paving. Sandstone Colours: Sandstone is available in a wide range of colours, some subtle and some vivid. The ranges comprise of a selection of core colours combined with subtle contrasting shades, and the balance of shades can vary between batches of even the same stone due to different seams in the stone quarry occurring over time. The colour intensity increases when the paving is wet. Most brands offer the same range of colours with slightly different names. BE AWARE that not ALL sandstone is the same quality - some unknown brands may not have been tested for suitability in the UK climate and may crack during cold weather.