The production of polycrystalline ceramics from YIG powders, obtained by reacting Y2O3 and Fe2O3 oxides, is a well understood and controlled industrial process. However, methods of production via chemical pathways, such as coprecipitation, possess the advantage that the garnet powder is more reactive and no longer requires prolonged grinding which can affect its purity. In this paper, we will show that the mastering of these two processes enables the production of ceramics possessing good magnetic characteristics for microwave applications.