Peridotite melt spreading light in the oven

During melting-quenching experiments on fragments from the Balmuccia peridotite. the magma is spreading its light in the oven.
You can see, from the top of the cylindrical oven, a platinum wire. The wire holds a platinum crucible, from which the magma shines. Platinum is used because of its high melting point, above 1700 °C, when total melting of peridotite is achieved below 1300 °C.
After sample recovery and polishing, SEM pictures show a biphasic glass: metal oxides in dense spheres and a lighter silicate phase. Around the spheres a myriad of (sub)micrometric crystals formed.