We’ve added more to our personal collection of rocks and minerals.
We bought this new batch from a Rocks, Minerals and Lapidary festival held in Goulburn, NSW at the end of 2009. They also appear in my book The Hidden Land along with the rest of the collection published here and some that are yet unpublished (in RB).
Best viewed larger…really
_Hematite, also spelled as hæmatite, is the mineral form of iron(III) oxide (Fe2O3), 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°C.
Hematite is a mineral, 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 (pseudomorphs after magnetite), iron rose and specularite (specular hematite). While the forms of hematite vary, they all have a rust-red streak. Hematite is harder than pure iron, but much more brittle. Maghemite 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 in the United States. The mineral can precipitate out of water and collect in layers at the bottom of a lake, spring, or other standing water. Hematite can also occur without water, however, usually as the result of volcanic activity.
Clay-sized hematite crystals can also occur as a secondary mineral formed by weathering processes in soil, and along with other iron oxides or oxyhydroxides such as goethite, is responsible for the red color of many tropical, ancient, or otherwise highly weathered soils.
Good specimens of hematite come from England, Mexico, Brazil, Australia, United States and Canada.
The name hematite is derived from the Greek word for blood αἷμα aima 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. The original name of the stone was αἱματίτης λίθος (haimatitēs lithos, “blood-red stone”).
Ochre is a clay that is colored by varying amounts of hematite, varying between 20% and 70%. Red ochre contains unhydrated hematite, whereas yellow ochre contains hydrated hematite (Fe2O3 • H2O). The principal use of ochre is for tinting with a permanent color.
The red chalk winning of this mineral was one of the earliest in history of mankind. The powdery mineral was first used 164,000 years ago by the Pinnacle-Point man obviously for social differentiation4. Hematite residues are also found in old graveyards from 80,000 years ago. Near Rydno in Poland and Lovas in Hungary, palaeolitic red chalk mines have been found that are from 5000 BC, belonging to the Linear Pottery culture at the Upper Rhine.
Rich deposits of hematite have been found on the island of Elba that have been mined till the time of the Etruscans._