Stellar Grain Composition-Abundances from BCC0001, plotted against Cosmic Abundances inferred by remote spectral instrumentation. Laboratory analysis vs. remote sensing.

     January 2004,
    S.Ray DeRusse and Bill Cutler
      updated, 2-5-04
    As the only stellar grain hand sample found thus far, BCC0001 provides a unique  opportunity to verify the abundant work completed or under way in stellar chemical composition and evolution. In analyzing the hand sample grains by XRD and EDS we provide a unique fingerprint for stellar grain composition from analysis of the sample and show the difference between the remote sensing data composition and the crystallized hand sample.
In an application closer to home and directed towards Earth, Frank T. Dulong of the USGS writes;
     Mineralogical analysis by XRD is used in conjunction with remotely sensed data in several research investigations.  XRD is used to identify the minerals composing clay rich, hydrothermally altered rocks that occur on several Cascade volcanos. Such rocks are believed to play an important role in the generation of large landslides and mud flows. XRD  is used to analyze saline minerals, including borates. Many saline hydrated minerals produce diagnostic spectral bands, and spectral data provide a basis for mineral exploration using remote sensing data. Analysis of airborne imaging spectrometer data can directly map mineral occurrences by detecting diagnostic spectral bands, the shape and position of which are determined by individual mineral structures. A detailed knowledge of sample mineralogy, provided at least in part by XRD, is required to understand the observed spectral absorption features.

Figure 1 below shows abundances of the chemical elements in the solar system in terms of  atoms per 106 of Si.
The data were derived primarily by analysis of Carbonaceous Chondrite and by optical spectroscopy of light from the Sun and nearby stars (Anders and Ebihars, 1982).

Figure 1
    In the figure 2 below, Kotz and Purcell write and show:

“The cosmic abundances of the lighter elements as a function of atomic number. Abundances are expressed as numbers of atoms per 1012 atoms of Hydrogen and are plotted on a (base-10) logarithmic scale.  Data taken from G.O. Abell, Exploration of the Universe, 4th ed. Saunders College Publishing. Philadelphia, 1982, p.706.”
Figure 2
Kotz and Purcell further write:

“The composition of a number of stars in the universe and of the planets and moons of  our solar system has been determined. It is of great relief to find that there is no evidence for an element found in some distant star that does not exist on Earth. Further, although there are variations from star to star and planet to planet, the relative abundances of the elements are approximately the same. These are very important observations since they mean that the element-forming processes are general through out the universe. The relative abundances of a few of the elements are illustrated above. The most striking features of this figure are those that follow and of the facts that must be taken into account in any theory of the origin of the elements.”

(a)   90% to 95% of the atoms in the universe are Hydrogen atoms.
(b)    5% to 10% of all atoms are Helium.
(c)    All of the other elements taken together make up only about 1% of the universe, even on weight basis.
(d)    Lithium, Beryllium, and Boron are mysteriously rare.
(e)    Elements of even atomic number are more abundant than those with odd atomic number.
(f)     There is a general decline in abundance from oxygen to lead. However, there is a very pronounced maximum in relative abundance around iron.
(g) There are no stable elements with mass numbers greater than 210.
In explaining and speaking to (f) above, on the pronounced maximum in relative abundance around iron, Professor Steven I. Dutch of The  Department of Natural and Applied Sciences, University of Wisconsin Green Bay, in Journal of Chemical Education, Vol. 76 No. 3, March 1999. Periodic Tables of Elemental Abundance writes:
  "In the later stages of evolution of stars much more massive than the sun, additional cycles of nuclear fusion form elements heavier than carbon. The end result of fusion is iron, the most tightly bound nucleus. Iron nuclei cannot yield energy by either fusion or fission, and nuclei beyond iron form via two processes. One the s-process (for slow) involves stray collisions between nuclei and other atomic particles. Obviously, the more particles added, the rarer the element will be. The other process the r-process (for rapid-and how)." "The relative abundance peak of iron is due to its being the most tightly bound nucleus and the end of stellar energy production. The tailing off of heavy elements beyond iron is due to the steadily increasing difficulty of constructing heavy nuclei in both the s- and r-processes.
    As we find in the patterns below there is a steady (logarithmic) decrease in heavier elements as a function of atomic mass over the entire chemical range, i.e. there are less and less crystals in solution of heavier elements as the atomic mass increases. See also Manuel and Katragada, The Sun's Origin and Composition: Implications From Meteorite Studies.  This study propels the argument that:
"In the 1970's meteorite studies indicated the Sun might be a supernova remnant. Decay products of short- lived  nuclides, nucleogenetic isotopic anomalies in meteorites, and evidence of mass separation in the Sun confirmed that iron is the Sun's most abundant element."  Manuel and Katragada further write:" Application of Eq (1) [see entire paper], to the photosphere further confirms prediction c):  Iron (fe), Nickel (Ni), Oxygen (O), Silicon (Si), Sulfur (S), magnesium (Mg), and Calcium Ca) are the Sun's most abundant elements. These are even numbered elements that are made inside supernovae; the same elements Harkins found to comprise 99% of ordinary meteorites."

   
stellar grain thin section
       Clearly Kotz and Purcell in this one small section of their chemistry book (Chemistry and Chemical Reactivity, CBS College Publishing, 1987), have pulled together  much research and "crystallized" and satisfied in one fell swoop our visual sense of the near Universe. But there is no substitute for having a hand sample of stellar grains in the lab. At left is the thin section of stellar grains that produced the characteristic X-ray diffraction  intensity patterns and peaks shown above, and beautifully confirm the works of Kotz, Purcell, Manuel, Katragada and many others.  This page contains the oxide abundances for six stellar grains from data taken by energy dispersive spectroscopy, (EDS analysis).




BCC Meteorites gratefully acknowledges AMIA Laboratories, a division of Rigaku MSC, Dr. Richard Ortega, Ms. Delrose Winter and Bernard Squires for your assistance and expertise in providing us with the tools used in confirmation and discovery. We want to congratulate you as being the first Laboratory anywhere in the world, public or private, in analyzing the very first mass of stellar grains! Congratulations!