Can somebody please help. I found this rock on the beach in the south of England. It seems to have a number of small shards of what look like crystal or glass spread around it whilst the rock itself has an overall sheen. The pictures don't do it justice. There is also a copper/bronze coloured ore attached to it.
The bronze coloured stuff is hard. I am struggling to scrape anything of it the whole thing seems pretty solid. I can make a scratch mark on the bronze coloured bits but the grey part doesn't mark. To be honest I'm damaging my knife more.
After scraping for some time I find that the small amounts of lighter coloured bronze comes away with a grainy texture. Although I'm not an expert I presume this to be sand which has accumulated over time and compacted to make it hard. The larger amounts of dark bronze do not, this is a lot tougher. When scraping at it my knife seems to leave a kind of silver mark, which fades when rubbed. It's as if the knife is somehow scraping off onto the rock?