Hematite (1) Raw Minerals Stones Rocks Collecting

Description

Origin : Brazil

Hematite 21-40 gr - cm 2-3.5 Raw Minerals Stones Rocks for Collection.

Hematite is an iron oxide, a fairly common mineral in nature. The name derives from the Greek for the blood red color that the mineral sometimes assumes in a crystalline state.
From the use of hematite in the graphic arts comes the term "pencil", as this material was used to produce the first pencils.
The mineral is found in many effusive rocks, in the pegmatites and in the hydrothermal veins where the residual magmas consolidate, however the sedimentary genesis by diagenesis of limonite is not lacking.
The main deposits are however related to a unique and unrepeatable event in the history of the planet, in stratified ferrous formations testifying to the appearance of free oxygen in the atmosphere and hydrosphere by the first processes of chlorophyll photosynthesis of blue-green bacterial algae.
The main industrial producing countries are Angola, Australia, Spain, Chile, South Africa, Venezuela, Brazil, Liberia, Mauritania, Norway, Sweden.
Even today it is possible to find splendid crystallized specimens in various Italian regions; famous are the crystals found in the landfills of the mines of the Island of Elba.
The mines on the island of Elba have been operating since the Etruscan era, as evidenced by the remains of ferrous slag found in the vicinity of Populonia where the hematite was transported for processing.
Excellent tabular and lamellar crystals have been found in the fumaroles of some volcanoes, including Vesuvius, Etna, Stromboli. The Alps provide the "iron roses"; among the places to remember are the Gotthard Pass and many places in Ossola.
The crystals maintain the octahedral or rhombododecahedral structure original of the magnetite, they have a steel black color and a very lively luster, or they are opaque. Some samples are weakly magnetic from a residual magnetism of the magnetite.