Name/Title
Chlorite PhantomEntry/Object ID
2004.1.150Description
Chemical Composition: (Fe, Mg, Al)6(Si, Al)4O10
Crystal System: Monoclinic System
Description: Common Name: Chlorite Phantom
Group Name: Chlorite
Chemistry: (Fe, Mg, Al)6(Si, Al)4O10(OH)8
Location:
Description:
PHYSICAL CHARACTERISTICS:
Color is usually green but can also be white, yellow, red, lavender and black.
Luster is vitreous, dull or pearly.
Transparency: Crystals are translucent transparent.
Crystal System is monoclinic; 2/m.
Crystal Habits: Rarely in large individual barrel or tabular crystals with an hexagonal outline. Usually found as alteration products of iron-magnesium minerals and as inclusions in other minerals. Aggregates can be scaly, compact, platy and as crusts.
Cleavage is perfect in one direction, basal; not seen in massive specimens.
Fracture is lamellar.
Hardness is 2 - 3
Specific Gravity is variable from 2.6 - 3.4 (average to slightly above average)
Streak is pal green to gray or brown.
Other Characteristics: Cleavage flakes are flexible but not elastic.
Associated Minerals include garnets, biotite, quartz, magnetite, talc, serpentine, danburite, topaz and calcite, among many others.
Best Field Indicators color, cleavage, associations and crystal habits.
Fracture: lamellar
Hardness: 6 Orthoclase
Luster: Metallic
Occurrence: Notable Occurrences include Transvaal, South Africa; Zermatt, Switzerland; Guleman, Turkey; Lancaster Co., Pennsylvania, Brewster, New York; San Benito Co., California, USA and many other locallities world wide.
Chlorite is commonly found in igneous rocks as an alteration product of mafic minerals such as pyroxene, amphibole, and biotite. Chlorite is a common mineral associated with hydrothermal ore deposits and commonly occurs with epidote, sericite, adularia and sulfide minerals. In this environment chlorite may be a retrograde metamorphic alteration mineral of existing ferromagnesian minerals, or it may be present as a metasomatism product via addition of Fe, Mg, or other compounds into the rock mass. Chlorite is also a common metamorphic mineral, usually indicative of low-grade metamorphism. It is the diagnostic species of the zeolite facies and of lower greenschist facies. It occurs in the quartz, albite, sericite, chlorite, garnet assemblage of pelitic schist. Within ultramafic rocks, metamorphism can also produce predominantly clinochlore chlorite in association with talc. Experiments indicate that chlorite can be stable in peridotite of the Earth's mantle above the ocean lithosphere carried down by subduction, and chlorite may even be present in the mantle volume from which island arc magmas are generated.
Chlorite occurs naturally in a variety of locations and forms. For example, chlorite is found naturally in certain parts of Wales in mineral schists.[1] Chlorite is found in large boulders scattered on the ground surface on Ring Mountain in Marin County, California.[2]
Specific Gravity: 2.6-3.4
Streak: pale green
Variety: Chlorite is a general name for several minerals that are difficult to distinguish by ordinary methods. These minerals are all apart of the Chlorite Group of minerals. The chlorites are often, but not always considered a subset of the larger silicate group, The clays.
For practical reasons most of the chlorites will be considered here as a single mineral, chlorite. Chlorites are generally green and crystallize in the monoclinic symmetry system. They all have a basal cleavage due to their stacked structure. Chlorites typically form flaky microscopic crystals and it is this reason that they are sometimes included in the clay group of minerals. However chlorites also form large individual tabular to platy crystals that are unlike most of the other clay minerals.
Chlorites are most often known to mineral collectors as inclusions in or coatings on quartz, danburite, topaz, calcite and many other minerals. The inclusions are usually a very strong green color despite the small amount of material that actually constitutes the inclusion. These inclusions and coatings can be an enhancement but are more often a bane to what might have been a really valuable mineral specimen.
The chlorite inclusions in clear quartz are particularly interesting when they form as a coating on a crystal early in its development. Because if the crystal later grows larger, ie. out and around the chlorite coating, the effect will be to produce a phantomed crystal. A phantom is a crystal that appears to have a smaller crystal inside of it. Many times the interior "crystal" is indistinct or ghostly and thus the name phantom.
There are many minerals that make up the chlorites and thus many varieties. One variety is called kaemmererite and is a variety of the chlorite clinochlore. Sometimes kaemmererite is called chromian clinochlore because of the increase chromium content. It is the chromium that gives kaemmererite its bright lavender to deep crimson red color.Collection
Suomynona Mineral CollectionAcquisition
Accession
2004.1Source or Donor
Suomynona Mineral CollectionAcquisition Method
DonationDimensions
Width
3 inDepth
2-1/2 inLength
2 inDimension Notes
Dimension taken at widest pointsLocation
Location
Room
Neil JohnsonBuilding
Attic StorageCategory
PermanentMoved By
Lehman R.Date
August 28, 2009Location
Container
CenterDrawer
Front Row / 2nd ShelShelf
Right, RightWall
NorthBuilding
Founders RoomCategory
PermanentMoved By
Lehman R.Date
August 28, 2009Location
Shelf
LeftCabinet
Case # 7Room
Mentzer HallBuilding
Crater Rock MuseumCategory
Permanent
