III. Iron Flashcards
(58 cards)
What is the luster of iron?
Lustrous
Is iron ductile or brittle?
Ductile
Is iron malleable or rigid?
Malleable
What color is iron in its pure form?
Silver-gray
What is the specific gravity range of iron?
7.3 – 7.87
What is the hardness of iron on the Mohs scale?
4.5
How does iron react to a magnet?
It is strongly attracted by a magnet.
What is the ranking of iron in terms of abundance among elements in the Earth’s crust?
4th most common element
Among metallic elements, where does iron rank in terms of abundance?
2nd most abundant metallic element
What is the shiny, metallic variety of Hematite called?
Specularite
What is the earthy, reddish variety of Hematite called?
Red Ochre
What is the chemical formula of Magnetite?
Fe₃O₄ (ferrous oxide)
Philippine iron deposits are classified into:
Skarn (or contact metasomatic), Magnetite sand, Laterite, Sedimentary, Bog, Spring
What is the chemical formula of Hematite?
Fe₂O₃ (ferric oxide)
Which iron mineral has the formula Fe₂O₃·3H₂O?
Limonite (ferric oxide trihydrate)
Which iron mineral commonly occurs as rhombohedral crystals and is often associated with sedimentary deposits?
Siderite
What iron mineral forms as a product of weathering and oxidation of iron-rich minerals?
Goethite
Which iron mineral is typically found in earthy, yellow-brown masses?
Limonite
Which iron mineral is known for its strong magnetic properties?
Magnetite
What is the chemical formula of Siderite?
FeCO₃ (ferrous carbonate)
What is the chemical formula of Goethite?
FeO·OH
What is the most important type of iron deposit in the Philippines?
Skarn
What geologic setting do iron skarn deposits in the Philippines occur in?
In a setting where limestone or calcareous sediments are intruded by a younger intermediate to acidic pluton.
Where is the skarn developed in relation to the intrusive contact?
Not far from the margins of the intrusive contact into the metasomatized limestone/calcareous sedimentary rock.