Very Rare Hematite Var. Martite (Pseudomorph after Magnetite) – Location: Thomas Range, Juab Co., Utah. Miniature (see photo for more details). Here we have a very rare specimen from the famous Thomas Range in Utah; we have hematite replacing magnetite crystals known as martite. Martite is the name given to hematite that has replaced or “pseudomorphed” magnetite crystals. This specimen is composed of numerous well formed and sharp octahedral crystals and the crystals are a black color. They form as relatively sharp crystals of hematite that has replaced the original magnetite crystals but maintain the original shape of the magnetite. Such martite crystals were only found in very limited numbers from only one isolated cavity from the Thomas Range durangite/cassiterite locality. In all there were only 25 specimens from this cavity. This specimen should definitely be of interest for people interested in minerals from the Thomas Range. This specimen is from the John Holfert collection.