Comments on: An Entirely Possible Legend: Vikings Steered Ships Using “Sunstones”

By: Meoww

Meoww — Tue, 11 Oct 2011 15:57:00 +0000

yo dsa erk duh redd

By: Tony Konrath

Tony Konrath — Tue, 01 Feb 2011 16:20:08 +0000

The material that was most available and that actually works is Iolite, sometimes called “Water sapphire” or “Vikings’ compass.”

It’s even possible to set this stone as a cabochon into a ring or a pendant and still use it to detect the sun’s position.

Tony Konrath F.G.A.

By: Amos Zeeberg (Discover Web Editor)

Amos Zeeberg (Discover Web Editor) — Mon, 31 Jan 2011 18:39:55 +0000

Hi, Georg. I disagree on your first point: minerals come in all kind of different forms, depending on impurities, how the crystals were (ahem) formed, etc. Look at this image of different forms of calcite: http://gwydir.demon.co.uk/jo/minerals/calcite.htm

On the second point, from the wording it’s not clear whether Nature (which is where that quote is from) is saying that Icelandic spar is common in Scandinavia or that the bigger category of calcite is common in Scandinavia. A quick Web search turned up a bunch of different Norwegian mines that produce calcite (e.g. http://bit.ly/f3Y6Sh), so I think we should give them the benefit of the doubt and say the claim may well be right.

By: Georg

Georg — Mon, 31 Jan 2011 17:49:49 +0000

“Icelandic spar, a transparent form of calcite, which is common in Scandinavia.”

There are two
misconceptiones in this sentence_
- calcite is calcite, there a no “formes of “! A calcite may be a big crystal, or
a conglomerate of smaller crystals and hence apeeares “white”, but all is calcite.
- The big clear calcites a specialty if Iceland, not common in all Scandinavia.
Truth is, Scandianavia is poor in limestone, some is found in Denmark, that is all.
Georg