longmrclogo.gif (25976 bytes)


NEW ACQUISITIONS


New additions are added throughout this list.  

Gibeon, Hardap Region, Great Namaqualand, (South West Africa) Namibia  

See specimens below.


Type:  Iron (IVA) fine octahedrite

Basic Information

  • Location: Latitude 25 degrees 20 minutes South, Longitude 18 degrees East.

  • Structural Class: Fine octahedrite, Of (= octahedrite, fine), Widmanstatten bandwidth 0.3 ±0.5 mm.

  • Chemical Class: Group IVA, 7.93% Ni, 0.41% Co, 0.04% P, 2.0 ppm Ga, 0.12 ppm Ge, 2.3 ppm Ir.

  • Time of Fall: In prehistoric times.

 History

 The Gibeon Meteorite was first reported by Capt. J.E. Alexander in 1838.  He heard of masses of native Iron up to two feet square, located on the east side of the Great Fish River.  In the years following, Europeans established large cattle ranches in the area and recovered many more large meteorites.  A 232 kg mass was recovered in 1857.  Many masses between 100 and 500 kg were recovered in the years shortly after 1900.  As late as the publication of the “Handbook of Iron Meteorites” in 1975, scientists were reporting that the Gibeon meteorite consisted primarily of large masses, and that smaller pieces like those found at Canyon Diablo, Odessa, and Sikhote-Alin, were unknown.  Buchwald speculated that additional exploration might reveal smaller specimens.  Additionally, it has been speculated that many of the smaller fragments may have been collected by natives and made into tools. It seems that lack of knowledge may have been the answer.  In the past year or two increasing numbers of small Gibeon meteorites have been exported.  It may be that with modern metal detectors, meteorite hunters will locate a substantial number of smaller specimens in the future.

 Composition and Mineralogy

 The chemical composition of the Gibeon is:

  • 90% iron

  • 8% nickel

  • 0.4% cobalt

  • 0.04% phosphorus.

The minerals identified in Gibeon meteorites are:

  • Kamacite, Taenite make up 99% + of the meteorite

  • Troilite (an iron sulfide) is common as nodules and in recrystallized forms.

  • Chromite (chrome oxide) is found occasionally

  • Daubreelite is found in the Kamacite.

  • Enstatite (a silicate mineral -- Pyroxene) is rare.

  • Tridymite (a silicate mineral) is rare.

 Etched Gibeon meteorite specimens usually display a fine Widmanstatten structure (fine octahedrite).  Oxidization (rusting) is usually not a problem with Gibeon specimens, due to the high Ni content of the meteorite.  Taenite (Fe,Ni), is the source of the nickel.  Troilite inclusions can be seen on all of the specimens listed below, though some of the Troilite inclusions are very small.  Item D has unusually rich amounts of Troilite.

 See the table at the bottom of the page for definitions of the abbreviations in the PREPARATION column.

 

ITEM NO.

WEIGHT(GRAMS)

SPECIMEN SIZE
(INCHES)

     PREPARATION

PRICE  /
GRAM

SPECIMEN
PRICE

ME-435 K

425.50

1 3/4

1 3/8

1 1/4

C (5), ET (5), NB

$ 1.50

SOLD

ME-435 L

629.40

2 5/8

2 5/8

1 1/8

C (3), ET (3), NB

$ 1.35

$849.50

ME-435M

145.95

2 3/4

2 3/4

1/16 to 1/8

PS, ET (5),
NE (1)

$ 1.90

SOLD

 

References:

1.      “Iron Meteorites”, V. F. Buchwald, Vol. 2, P. 584-593 (1975).

2.      “Catalogue of Meteorites”, 5th Edition, M. Grady, The Natural History Museum, P. 214 (2000).

3.      “Meteorites From A to Z”, M. Jensen et al, 2nd Edition, P. 48 (2004).

4.      “The Meteorite Market”, www.meteoritemarket.com/GNinfo.htm
 

Preparation:

C   = cut (   ) = quantity of cuts                    NB    = natural back

ET = etched w/ Widmanstatten pattern      NE    = natural edges

FS  = full slice                                               POL = polished surface      

                                                                      PS    = part slice        


ME-435K FRONT

ME-435K BACK

ME-435 LEFT SIDE

ME-435 RIGHT SIDE

M3-435 TOP

ME435L FRONT

ME-435L BACK
     

ME-435M FRONT

ME-435 BACK
     

 

                            MORE PHOTOS 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Copyright 1998-2017 by Mineralogical Research Co.
All rights reserved.