Shortite
Current inventory: 1 gem
 

  
Shortite was named to honor Dr. Maxwell Naylor Short (1889-1952), professor of mineralogy, University of Arizona, Tucson, Arizona, USA.

Discovered in 1939; IMA status: Valid (pre-IMA; Grandfathered)

Chemistry

Chemical Formula:

Na₂Ca₂(CO₃)₃

Sodium Calcium Carbonate

Molecular Weight:

306.16 gm

Composition:

Sodium

15.02 %

Na

20.24 %

Na₂O

Calcium

26.18 %

Ca

36.63 %

CaO

Carbon

11.77 %

C

43.12 %

CO₂

Oxygen

47.03 %

O

100.00 %

100.00 %

= TOTAL OXIDE

Classification

Mineral Classification:

Carbonates

Strunz 8th Ed. ID:

5/B.05-70

Nickel-Strunz 10th Ed. ID:

5.AC.25

5 : CARBONATES (NITRATES)
A : Carbonates without additional anions, without H₂O
C : Alkali and alkali-earth carbonates

Related to:

Eitelite-Shortite-Carbocernaite Series

Crystal Data

Crystallography:

Orthorhombic - Pyramidal

Crystal Habit:

Crystals are typically wedge-shaped, tabular to short prismatic, to 3 cm, striated.

Twinning:

None

Physical Properties

Cleavage:

Distinct on {010}

Fracture:

Conchoidal

Tenacity:

Brittle

Hardness (Mohs):

3.0 - 4.5

Density:

2.600 - 2.629 (g/cm³)

Luminescence:

Pale amber fluorescence under SW UV

Radioactivity:

Not Radioacitve

Other:

Strongly Pyroelectric. Water Soluble; decomposed by water with separation of CaCO3.

Optical Properties

Color:

Colorless, light Yellow, dark Yellow, light Green

Transparency:

Transparent

Luster:

Vitreous

Refractive Index:

1.531 - 1.570  Biaxial ( - )

Birefringence:

0.0390

Dispersion:

Moderate; r < v

Pleochroism:

X = colorless, Y = colorless, Z = colorless

Occurances

Geological Setting:

In saline dolomitic marl (Green River Formation, Wyoming and Utah, USA); in kimberlite dikes (Upper Canada mine, Canada); in carbonatite (Vuoriyarvi massif, Kola Peninsula, Russia); in differentiated alkalic massifs (Kovdor and Khibiny massifs, Kola Peninsula, Russia); associated with an intrusive alkalic gabbro-syenite complex (Mont Saint-Hilaire, Canada).

Common Associations:

Nahcolite, Pyrite, Trona (Green River Formation, Wyoming and Utah, USA); Apatite, Calcite, Magnetite, Olivine, Perovskite, Phlogopite (Upper Canada mine, Canada); Albite, Barentsite, Natrite, Natrolite, Villiaumite (Khibiny massif, Kola Peninsula, Russia)

Type Locality:

John Hay Jr. Well No. 1, Green River Formation, Sweetwater County, Wyoming, USA

Year Discovered:

1939

View mineral photos:

Shortite Mineral Photos and Locations

Unusual Gem Categories

Pyroelectric Gems, Water Soluble Gems

More Information

Mindat.org
Webmineral.com

According to the Color Encyclopedia of Gemstones by Joel Arem, "Shortite is an exceedingly rare mineral. Cut gems are among the rarest of all faceted stones. The material is a carbonate and is therefore fragile and soft." The mineral ranges from colorless to pale yellow. Shortite was first described by J.J. Fahey of the U.S. Geological Survey as a new mineral in 1939. It was discovered in oil well drill cores from the Green River Formation, Sweetwater County, Wyoming. Shortite is soft and fragile, with a perfect cleavage and the large birefringence typical of a carbonate mineral. The fact that it decomposes in water makes it very difficult to facet. Small, colorless gems have been faceted from the crystals found at Sweetwater County. These gems show pale amber fluorescence under shortwave UV light. Yellow crystals of Shortite were discovered at Mont Saint-Hilaire, Québec, Canada in 1991, and a small quantity of gems were faceted from transparent pieces.

Shortite was named to honor Dr. Maxwell Naylor Short (1889-1952), Professor of Mineralogy, University of Arizona, Tucson, Arizona, USA. During World War I Short lost both legs in a mine explosion while serving with the 319th Engineers at Camp Fremont, California. This loss handicapped him greatly but did not stop him from doing a great deal of field work and making great contributions to the fields of geology and mineralogy. He was a Fellow of the Mineralogical Society of America and was elected its president in 1939. He was a Fellow of the Geological Society of America and vice-president of that organization in 1940. He was an active member of the American Institute of Mining and Metallurgical Engineers, and the Society of Economic Geologists. He served for many years as one of the associate editors of The American Mineralogist, until the time of his death.

Shortite distribution: n the USA, from the Green River Formation, Wyoming and Utah, with indicated reserves of billions of tons; found in the John Hay, Jr. Well No. 1, about 30 km west Green River, Sweetwater County, Wyoming; and in the Uintah Basin, northeastern Utah. In Canada, in the Upper Canada gold mine, Kirkland Lake district, Ontario, and at Mont Saint-Hilaire, Quebec. In Russia, on the Kola Peninsula, in the Vuoriyarvi carbonatite complex, from the Kovdor massif, and on Mt. Restin’yun, Khibiny massif; from the Udachnaya pipe, Daldyn kimberlite field, Sakha.
 

  
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