Name/Title
CalciteEntry/Object ID
2009.62.198Description
Chemical Composition: CaCO3
Crystal System: Tetragonal System
Description: Chemistry: CaCO3
Class: Carbonates
Group: Calcite
PHYSICAL CHARACTERISTICS OF CALCITE:
Color is extremely variable but generally white or colorless or with light shades of yellow, orange, blue, pink, red, brown, green, black and gray. Occasionally iridescent.
Luster is vitreous to resinous to dull in massive forms.
Transparency: Crystals are transparent to translucent.
Crystal System is trigonal; bar 3 2/m
Crystal Habits are extremely variable with almost any trigonal form possible. Common among calcite crystals are the scalenohedron, rhombohedron, hexagonal prism, and pinacoid. Combinations of these and over three hundred other forms can make a multitude of crystal shapes, but always trigonal or pseudo-hexagonal. Twinning is often seen and results in crystals with blocky chevrons, right angled prisms, heart shapes or dipyramidal shapes. A notch in the middle of a doubly terminated scalenohedron is a sure sign of a twinned crystal. lamellar twinning also seen resulting in striated cleavage surfaces. Pseudomorphs after many minerals are known, but easily identified as calcite. Also massive, fibrous, concretionary, stalactitic, nodular, oolitic, stellate, dendritic, granular, layered, etc. etc.
Cleavage is perfect in three directions, forming rhombohedrons.
Fracture is conchoidal.
Hardness is 3 (only on the basal pinacoidal faces, calcite has a hardness of less than 2.5 and can be scratched by a fingernail).
Specific Gravity is approximately 2.7 (average)
Streak is white.
Best Field Indicators are crystal habit, reaction to acid, abundance, hardness, double refraction and especially cleavage.
Fracture: Conchoidal
Hardness: 3 Calcite
Luster: Vitreous
Occurrence: Notable Occurrences include Pugh Quarry, Ohio; Rosiclare, Illinois; Franklin, New Jersey; Elmwood, Tennessee; Brush Creek and other Missouri, Wisconsin, Kansas and Oklahoma localities, USA; Andreasburg, Harz Mountains and Saxony, Germany; Brazil; Guanajuato, Mexico; Cornwall, Durham and Lancashire, England; Bombay area of India; Eskifjord, Iceland; many African localities as well as others around the world with their own unique varieties.
Notable Occurrences are extensive and include the Deccan Traps (ancient basalt flows) in India especially around Poona, also found in Christmas Mine, Arizona; Fairfax, Virginia; Upper Peninsula, Michigan; Oregon; Pennsylvania; Paterson, New Jersey and North Carolina, USA; Rio Grande do Sul, Brazil; Isle of Skye, Scotland; Collinward, Northern Ireland; Mexico; Nova Scotia and Mont Saint-Hilaire, Canada; Iceland; Kongsberg, Norway; Harz Mountains, Germany and Sampo Mine, Takahashi, Okayama, Honshu, Japan.
Rock Type: Sedimentary
Specific Gravity: 2.3
Streak: White
Variety: There are several varieties of calcite and it would be impossible to describe them all. However there are a few standouts. Possibly the most well known of calcite's varieties is its most common form, the classic scalenohedron or "Dogtooth Spar" as it is sometimes called. This variety appears as a double pyramid or dipyramid, but is actually a distinctly different form. The point of the scalenohedron is sharp and resembles the canine tooth of a dog, hence the name. Beautiful clear colorless or amber-orange examples of this variety are considered classics and outstanding examples come from Pugh Quarry, Ohio; Cornwall, England and Elmwood, Tennessee but the variety is found worldwide.Collection
RAGM Mineral CollectionAcquisition
Accession
2009.62Source or Donor
Museum Collection of MineralsAcquisition Method
DonationDimensions
Width
8 inDepth
3 inLength
10 inLocation
Location
Display Case
FS-6-ARoom
Frieda Smith HallBuilding
Crater Rock MuseumDate
January 3, 2024Location
Wall
NorthBuilding
Storage (old gift shop upstairs)Category
PermanentMoved By
Rawley WyattDate
May 16, 2014Location
Drawer
North side CenterShelf
Middle shelf, Middle shelfRoom
Delmar Smith HallBuilding
Crater Rock MuseumCategory
PermanentMoved By
Joshua EspongeDate
November 13, 2009Location
* Untyped Location
Needs Updated Location - 2022Category
Permanent
