HEMATITE

Description:

Hematite is an important ore of iron, is a mineral appearing as metallic gray, red gray, red brown with a metallic luster. The name hematite originates from the Greek word haima "blood", which refers to the dark red color of the mineral’s streak and the colour of its powder. The red, orange and brown colors occur when the iron in the hematite begins to rust. Once it is polished, it is a metallic gray and is usually smooth and rounded.

Crystals of hematite are considered rare. It forms in magmatic, hydrothermal, metamorphic and sedimentary environment. Hematite is also found in high-grade ore bodies in metamorphic rocks due to contact metasomatism, and occasionally as a sublimate on igneous extrusive rocks (lavas) as a result of volcanic activity.

Hematite appears in many forms in nature, such as Kidney Ore, a bumpy ore that has an appearance likened to a kidney; Hematite Rose, a formation with crystals in the shape of petals; Tiger Iron, a sedimentary rock with hematite mixed into its multiple layers; Oolitic, sedimentary deposits of small, circular hematite grains; and Micaceous Hematite, a scaly, shiny stone valued for decorative uses. Its soft Earthy form is called Red Ochre. Hematite often appears within other crystals such as aventurine or as phantom crystals.

The most notable occurrences of hematite are in Brazil (Matto Grosso), USA (Minnesota, Arizona and Alaska), in England, Russia and Czech Republic, as well as in Australia and New Zealand.

Hematite has probably been used since the earliest days of human civilization. The ancient Egyptians used Hematite in the creation of their magical amulets. Some of these amulets were treatments for madness and inflammation. Hematite relates to the Mars, the Roman God of War, so warriors in Roman times used Hematite as protection during battle. American Indians used to crush hematite and mix it with animal fat to produce red and brown paint for their artwork and their bodies. But most importantly, the chemical composition of hematite contains a high percentage of iron (70%) and it is the primary ore used to create iron. Jewelers appreciate its shiny luster for creating engravings, cameos, cabochons, beads and imitation diamonds.

Characteristics:

Chemistry: Fe2O3, Iron Oxide

Class: Oxides and hydroxides

Hardness (Mohs scale): 5 – 6.5

Density: 4.95 – 5.26

Refractive index: 2.94 – 3.22

Dispersion: none

Crystal system: trigonal

Crystal habits: tabular crystals of varying thickness, rarely prismatic or scalenohedral, also

rarely rhombohedral

Cleavage: none

Transparency: translucent on thin edges to opaque

Fracture: uneven, splintery, conchoidal