RP - Radial Pyroxene Chondrules

These are also called excentroradial chondrules. They are believed to have been completely melted and therefore lacked internal seed crystals from which larger crystals could grow. Thin fibers or laths grew from one or more points on the shell. When a radial pyroxene chondrule is cut these will often have a fan appearance but if the cut does not pass near a point from which crystals radiate it will look different.

 

 

 

 

The crossed polarizing filters between which this thin section lies are being rotated. As they rotate different pyroxene fibers go to optical extinction. There are two bundles of fibers. The larger, lower left, had its radiant point on the chondrule shell a little below the plane of this section. The other's was above. Sarir Qattusah 001 L/LL3

 

 

 

 

 

 

These radiating pyroxene laths are fairly coarse. The cracks in the crystals, perpendicular to their length, might have occurred during chondrule formation when a high temperature form of pyroxene transformed to the present form. NWA 1930 LL3, S2