giovedì 15 agosto 2013

A silica glass scarab of king Tut

by Siziliano

Figure 1: the glass scarab found in the
tomb of Tutenkhamon
Scarabs of Egyptian origin are found at places where nobody would expect them. They are sometimes SO UNEXPECTED that even the material from which they were made (ivory, bones, solid rocks and what not) are not recognized, not even by experts – and the epoch when they were handicrafted is matter of debate (they get older and older from day to day).

The recent discussion of an Egyptian scarab found in a site definitely identified as Sardinian has triggered me to keep my antennas open.

By chance, I stumbled over a TV transmission, where a scarab was studied found in a necklace found in the tomb of Tutenkhamon (see figure 1, one finds more photos of this type).

This scarab is clearly of glass, with a light-greenish, yellowish transparent texture. Assumptions that the material is of mineralic origin, were immediately discarded, the material is of amorphic, and not mineralic structure.

Rumors went on over the centuries that this type of glass exists and was found and exported for many times. Expeditions made in our times identified – important for the Egyptian culture – one site (there are only two sites known on earth) in the south-western corner of Egypt, close to the Lybian/Sudanese border. Here, one finds scattered over a large area, shards of this glass. Some details can be found via The National Geographic.

But let’s go on for another short moment. Scientists went over there and on the surface smoothed by the force of wind and sand, small pieces were found. When digging a bit deeper, more structured, sharp-edged glass fractures can be recovered. However, the shards are found on a large area, widely scattered over many square-kilometers.

So, what does one do? Geo-Chemists came on the stage. “Desert glass” fractions were analyzed. Chemical elements of Iridium, Osmium and Uranium are found. Uranium isotope relation identified an age of some 28 to 30 Million years.

Now we come to science fiction aspects of this: The ratio of the Osmium isotopes identified in the desert glass is not from Earth!! It is of EXTRA-TERRESTRIAN origin!! So, bloggists, heretics, take care!!

Figure 2. A desert glass specimen
This brings it to its origin: Desert glass was formed upon an impact of a meteorite, and it requires temperatures of at least 1800 °C!! The scientists even went to visit the sites of the first nuclear bomb experimental area. … and they found material of similarly amorphous composition (Figure 2).

But, back to the real world. This material has been used by the people living in this region already in the mid-to-neolithic era to generate axes and weapons for hunting: At that time the Sahara desert was a Savanna and full of animals for hunting. But through all times, the desert glass was understood as a material of high value worth for decorations for kings (and pharaos).

In fact, there is plenty to read on this – and, who knows whether one finds a scarab from desert glass in Sardegna? … always keep in mind: Glass, also this glass, is SiO2, ie., it simply is made of sand!