Superconducting qubits operating at microwave frequencies have shown great promise for quantum computation; however, they do not have an innate interface with optical photons in the telecommunication band. A quantum transducer is necessary for converting quantum information between microwave and optical frequencies. This presentation focus on quantum transduction using rare-earth ions in solid state systems, with a detailed discussion on the ion energy levels and transitions. We propose using magnetic materials with rare-earth dopants, harnessing the strong coupling between rare-earth spin transitions and magnons. We analyze this situation using a formalism similar to Ref. [PRL 113, 203601 (2014)]. We find that hosting rareearth elements within a magnet dramatically speeds up the transduction rate by more than two orders of magnitude, which gives several key benefits: potentially higher efficiency as it is less affected by device internal losses, higher fidelity operations with the superconducting qubits, and reduced device constraints.