Voussoir is a stone block which is usually used as a primary element for constructing an arch or vault. It is wedge shaped and each unit/brick that is used to form an arch is known as a voussoir. The term “Voussoir” is a technical term used by masons, adopted from the French verb which means turn. There are two functional units in voussoirs: keystone and springer. While constructing an arch, a keystone is used as either the centre stone or masonry unit at the top. On the other hand, a springer also known as lowermost voussoir is situated at a place from where the bend of an arch bounces from the vertical support or abutment of a wall. Voussoirs were seen in Eastern Romanesque and Arab architecture. Alternate colors, usually red and white were used in these voussoirs.