Very often I see in the market fake sovereigns for sale so we have to be careful and test any sovereign we are going to buy.
Recently, I photographed 2 examples that are fake so I can upload and show them to you. 1914 and 1918 George V sovereigns. As you notice in 1914 there are some Arabic symbols. These marks were used in sovereigns in period of war , and the purpose was cheating on purity of gold. The weight is normal but the purity is less than 0.917 gold.
Other marks of counterfeit displayed on asymmetry on rim. Also the weak pressing and the colour has to make us suspicious about genuine.
Be careful and dont buy with closed eyes.