MINERALOGICAL RESEARCH COMPANY



General physical features of the Fulgurites from
Great Sand Sea, Libyan Desert, Southwestern Egypt

TYPE IV (Tubular, with pronounced ridges)


OUTSIDE SURFACE:
FORM: The fulgurite specimens from this location are exceptionally attractive, with pronounced ridges running down the length of the fulgurite tubes.  In some specimens the ridges are slightly curved around, while at the same time running lengthwise down the fulgurite tubes.  Specimens with a distinctly different form were also recovered from this locality. These are flattened in cross section, with the ridges protruding straight out from the sides of the tubes, opposed at approximately 180 degrees. The two different forms are indicated on the accompanying table as:
    co =  Convoluted, with the ridges sometimes lace-like.  On this form, there is a tendency for the open tubes running down the interiors of the fulgurites to exhibit a slight curvature.              
    op = The ridges are opposed, with the fulgurite tubes exhibiting a fairly flat cross section. On this form, the open tubes running down the interiors of the fulgurites are usually in fairly straight alignment.
COLOR: Charcoal gray.
TEXTURE: Very rough, with numerous protuberances / ridges.
SAND GRANULES: White to light tan in color, small to fairly pronounced, highly fused and smooth.
GLASSY INTERIOR:
COLOR: Light smoky gray, to dark charcoal gray, translucent to opaque. 
TEXTURE: Smooth, glassy.
BUBBLES  (GAS
POCKETS)  PRESENT:
Microscopic, sometimes open, rather than healed by the flow of the molten Silica.


                           


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