Quantitative magnetic resonance imaging techniques such as quantitative susceptibility mapping (QSM) have great potential to provide tissue specific and longitudinally applicable biomarkers of disease. Such markers can potentially aid in not only the study of disease progression, but may also one day help inform the treatment of disease. Quantitative magnetic susceptibility mapping (QSM) is a nontrivial and powerful technique that directly measures the magnetization of tissue. The magnetization of tissue in the body is directly related to its composition and structure. The challenge in this work is that both the content and organization of tissue result in orientation dependent relaxation and magnetization, the complexity of which provides an opportunity to assess tissue microstructure and content from magnetic resonance field measurements. In this work, we will evaluate the reconstruction of magnetic susceptibility and relaxation tensors from MR field measurements and assess the contribution of major tissue components, such as iron and myelin, to measured tensor properties. This builds the theoretical and experimental ground work in translating measurements of tissue magnetization for applications in vivo.