Many minerals with metallic lusters produce a prominent streak (aka "true color") when rubbed on unglazed porcelain. For example, galena's streak is dark gray (very much like its appearance); however, that is not always the case. Which of the following best describes the streak for metallic gray specular hematite (Fe2O3)? a. red-brown
b. yellow
c. gray
d. black

Select the statements below that correctly describe where earth's three most abundant elements (iron, oxygen, and silica) are located. choose one or more: the majority of iron is located in the core. silica is abundant in the mantle and crust. the majority of oxygen is located in the crust and mantle. oxygen is only located in earth's atmosphere and is not found anywhere inside earth. silica is abundant in the crust, mantle, and core. no iron is located in the crust.