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About Minerals

Hematite (Fe2O3)

In jewelry design as in fashion, colors look crisper against a background of black, and black and white always looks right. In fine jewelry, the black backdrop is often supplied by onyx, a black chalcedony quartz with a fine texture. Some onyx also displays white bands or ribbons against a black background. If the layers are even, this type of onyx can be carved into cameos.

Hematite is the mineral form of iron, one of several iron oxides. Hematite crystallizes in the rhombohedral system, and it has the same crystal structure as ilmenite and corundum. Hematite and ilmenite form a complete solid solution at temperatures above 950 degrees.

Hematite is colored black to steel or silver gray, brown to reddish brown, or red. It is mined as the main ore of iron. Varieties include kidney ore, martite, iron rose and specular hematite. While the forms of hematite vary, all have a rust red streak. Hematite is harder than pure iron, but much more brittle. Maghematite is a hematite and magnetite related oxide mineral.

Huge deposits of hematite are found in banded iron formations. Grey hematite is typically found in places where there has been standing water or mineral hot springs, such as those in Yellowstone National Park. The mineral can precipitate out of water and collect in layers at the bottom of a lake, spring, or other standing water. The finding of grey hematite on Mars fuels speculation about water and life on the red planet. Hematite can also occur without water, however usually as the result of volcanic activity.

Opportunity Rover found that the soil at Meridiani Planum was very similar to the soil at Gusev crater and Ares Vallis, however in many places at Meridiani the soil was covered with round, hard spherules that were named “blueberries”. These blueberries were found to be composed almost entirely of the mineral hematite. It was decided that the spectra signal spotted from orbit by Mars Odyssey was produced by these spherules. After further study it was decided that the blueberries were concretions formed in the ground by water. Over time, these concretions weathered from what was overlying rock, and then became concentrated on the surface as a lag deposit. The concentration of spherules in bedrock could have produced the observed blueberry covering from the weathering of as little as one meter of rock. Most of the soil consisted of olivine basalt sands that did not come from local rocks. The sand may have been transported from somewhere else.

The name hematite is derived from the Greek work for blood, because hematite can be red, as in rouge, a powdered form of hematite. The color of hematite lends it well in use as a pigment.

Ochre is a clay that is colored by varying amounts of hematite—between 20% and 70%.

Red ochre contains unhydrated hematite, whereas yellow ochre contains hydrated. The principal use of ochre is for tinting with a permanent color.

The powdery mineral was first used 164,000 years ago by the Pinnacle Point man - for social differentiation. Hematite residues are also found in old graveyards from 80,000 years ago. In Poland and Hungary Paleolithic red chalk mines have been found that are from 5000 BC.

Rich deposits of hematite have been found on the island of Elba that have been mined since the time of the Etruscans. Ancient slag heaps were re-smelted using modern techniques during both world wars.

Hematite Healing Properties:

Hematite grounds and protects us. It strengthens our connections with the earth, making us feel safe and secure. It endows us with courage, strength, endurance and vitality. A “stone for the mind” Hematite stimulates concentration anad focus, enhancing memory and original thought.

From the Council Reporter, Oct. 2012