BCC9804, Cometary,
Showing the wide variation in crystal chemistry. Field of view special setup by Molecular Expressions to capture the Grain density approximately 4-6mm.

The two sets of photomicrographs above were taken at the edge of the slides. As the viewer can see, even the smallest crystalline particles at the edge of the sample help form the bonding matrix for the cometary grains and main mass. Even when cutting the sample with a diamond wet saw, the mass did not fracture nor break into smaller pieces. As previously mentioned, Comets should prove to be very cohesive and compact, and must be so to have survived the violent entry through Earths atmosphere. The purple material beyond the grains is the mounting medium having an RI of 1.54.

Above, a typical sub-mm cometary grain with a nucleus in the grain edge and below a grain with a grain collsion/compaction/penetration. Notice the
extremely tight boundary at the grain walls where the grains typically meet. The matrix surrounding the grains is composed of FeO in solution with other metals, alkalis, and alkali earths.

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