Name/Title
SideriteEntry/Object ID
2009.62.38Description
Chemical Composition: FeCO3
Crystal System: Triclinic System
Description: Common Name: Siderite
Chemistry: FeCO3, Iron Carbonate
Group: Carbonates
Location: Mount saint Hilane, Quebec, Canada
Description: The crystals are a cubic shape with a dirt brown color, has a white matrix.
PHYSICAL CHARACTERISTICS:
Color is gray, yellow, yellowish brown, greenish-brown, reddish brown and brown. Some specimens show an iridescence probably caused by surface alteration to goethite.
Luster is vitreous to pearly or silky in some specimens.
Transparency: Crystals are usually translucent or virtually opaque.
Crystal System is trigonal; bar 3 2/m.
Crystal Habits are commonly curved rhombohedrons that are sometimes flattened to appear bladed, rarely scalahedral. Many aggregate forms are also found such as botryoidal, sphericules (sphaerosiderite), concretionary, stalactitic, vein-filling and earthy.
Cleavage is perfect in 3 directions forming rhombs.
Fracture is conchoidal to uneven.
Hardness is fairly variable going from 3.5 - 4.5.
Specific Gravity is 3.9+ (relatively heavy)
Streak is white.
Other Characteristics: Becomes magnetic when heated, effervesces slightly in contact with strong acids or with warm acids.
Associated Minerals include iron sulfides and quartz, cerussite, ankerite, dolomite, goethite, cryolite, limonite, barite, pyrite and sphalerite.
Best Field Indicators are crystal habit, slight reaction to acids, cleavage, color and higher than average density
Fracture: conchoidal
Hardness: 3 Calcite
Luster: Vitreous
Occurrence: Siderite forms mostly in sedimentary and hydrothermal environments, although it is also found in some igneous pegmatites.
Rock Type: Sedimentary
Specific Gravity: 3.9
Streak: white
Texture: microcrystaline
Variety: Siderite is roughly the equivalent of calcite but with iron replacing the calcium. The iron has little effect on most structural properties such as cleavage and crystal form; but does effect properties such as density, color, hardness and electro-chemical properties. Siderite is fairly easy to distinguish from calcite by its higher specific gravity and hardness and less vigorous reaction to acids. It can be difficult to distinguish from dolomite however.
Siderite also forms a series with the closely related minerals rhodochrosite, MnCO3 and magnesite, MgCO3. These minerals can have some substitution of their metal ions and the cutoff between them and siderite is at 50% iron. Sometimes variety names are given to intermediate members of these minerals such as mangansiderite for an iron rich rhodochrosite or magniosiderite for a magnesium rich siderite.Collection
RAGM Mineral CollectionAcquisition
Accession
2009.62Source or Donor
Museum Collection of MineralsAcquisition Method
DonationDimensions
Width
6-1/4 inDepth
6 inLength
7-1/2 inWeight
8.41 ozDimension Notes
Dimension taken at widest pointsLocation
Location
Display Case
FS-6-ARoom
Frieda Smith HallBuilding
Crater Rock MuseumDate
January 3, 2024Location
Container
LeftDrawer
2nd shelfShelf
Right, RightWall
South wallRoom
Delmar Smith HallBuilding
Crater Rock MuseumCategory
PermanentMoved By
Wendy MondryDate
January 12, 2010Location
Container
Left / FrontDrawer
BottomShelf
LeftCabinet
Case #31Wall
EastBuilding
Freida Smith HallCategory
Permanent