FMF - Friends of Minerals Forum, discussion and message board

[centavar]

I recently acquired this quartz specimen and wondered how old it could be? I tried to research information on the subject, but it all seems to be very inconclusive and complicated. Can anyone give me a rough idea? The origin of the crystal is some Bulgarian mountain.

[Josele]

That depends of geological environment history but roughly could have from tens to hundreds of million years.

[cascaillou]

Considering that the crystal growth is dependant on the fluids, crystal growth rate can vary greatly depending on the fluid supply, and can even be interrupted for a long period and then start again.

This being said, large synthetic hydrothermal quartz can be grown within a few weeks.

[Mark Ost]

That is a bit of a difficult question with no easy answer. In a sense you are on the right track in that dating specific crystals can be quite useful as say dating certain Zircons to establish really old dates. Now the quartz can be a bit hard to pin down because different settings can grow crystals at a faster or slower rate. As one list member said "nature runs a messy laboratory." There are tests but they are complicated and all dating involves cross referencing with other tests to give a range of possible dates. It is not simple in practice to do, I fear. So the short of it is there can really can be no way to tell just by knowing what the mineral is. One idea would be to do some research into the formation or area it came from but that requires you know where exactly it was found. That may only get you in a very big ball park figure to guess at.

[cascaillou]

I think the questions needs clarification: is that about how long did it take for the quartz to grow to its final size, or is it about how long ago was the crystal formed?

By the way, a large synthetic quartz crystal can be grown within weeks, but how fast can a natural quartz grow? Can a natural quartz crystal grow to a few centimeters big within a few weeks?