Volume: 100ml +- 2% (yes, I couldn’t believe it either); Mass: measurement pending, but above 200g
I just bought a mineral identification book and it says to take a streak. I tried with tiles at home, but I am not sure which scratches which. If I don’t apply force, I see nothing. With enough force, I see very little white powder on the tile and white marks on the stone. I am not sure, whether the tiles are untreated. Here is the tile:
The stone is also harder than the coins I tried. They leave golden or red streaks on it.
The stone was given to me near Lafkos, 37006, Greece and probably found on a nearby beach, hence the rounded shape.
From the pictures in my book, I might guess green apatite, but I doubt it has the required density (book says between 3.16 and 3.22g/cm^3 I now try to determine weight and volume, but I have to ask my neighbours, because it exceeds the 200g limit of my precision scale.