Black rock with glassy crust
by Ann Buchanan
(Connel, ,Argyll, ScotlandUK. PA371PH)
I found it on a beach in Argyll on 12th August 2020, about the same time as the persied meteor shower. The block is a rhomboid shape with one narrow edge, is very heavy and attracted to a magnet. It is mostly matt black with faint reddy-brown veins branching through it also has speckles of silvery metal which can be seen when photographed with a flash.
The glassy surface is hard with one major groove interrupting the smooth surface and some chips round the edges. It is quite a big chunk (approx.11cmx11cmx5cm). I am sending photos showing the rock taken in daylight and also with a flash.