Dolomite - Solved? 

Many old rocks are dolomite, younger ones are seldom dolomite - why? 

There has been some activity in the dolomite field which shows that you can grow dolomite in the laboratory relatively quickly by repeatedly washing the growing crystal. 

(Dolomite crystals have layers of calcium, carbonate, magnesium, endlessly repeated. In the rocks there is no magnesium in the calcium layers and no calcium in the magnesium layers. Up to now this was impossible to replicate in the laboratory.)

The original paper which tells how to make dolomite is HERE. And "popular" readings of the paper are HERE and HERE and lots of other places.

This is very interesting but I am not sure that it tells us why dolomite is not being made in nature now.

Another annoyance is that the popular papers are obvious copies of each other - they all tell us that the White Cliffs of Dover are dolomite. At least that is not in the original.