Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: Dave_Sco on 30/08/2016 00:55:41

Title: What is this rock for?
Post by: Dave_Sco on 30/08/2016 00:55:41

I found this little round rock in my garden when digging in the clay. It has a density of 2g/cm^3 which is roughly around a rock of some sort. Diameter is around 1.75cm.

Just curious of what it would be for.

Title: Re: What is this rock for?
Post by: RD on 30/08/2016 06:40:25

There were bottles made with a ball inside ... https://en.wikipedia.org/wiki/Codd-neck_bottle
[ they were smashed by children to get the ball to play marbles ]

I'm sure I've seen one with an earthenware ball which looked like your find.

Alternatively the ball could be specifically-made as a play-thing ...
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.gettysburgaddress.com%2FGIFS%2Fmarbles.jpg&hash=4656d41d1680368522283431719c3516)
http://www.gettysburgaddress.com/HTMLS/Souvenirs-civil-war-relic.html

Title: Re: What is this rock for?
Post by: Dave_Sco on 30/08/2016 10:39:51

Thanks for the reply RD.

I am not sure about the codd-neck bottle design as they were made to be buoyant as to keep the bottle pressurized before opening. My stone is definitely not buoyant and would not seal correctly for the bottle design.

Now that you show me I can definitely see it being a clay marble for playing. We had quite a lot of them around Scotland.