Several things can cause mineral precipitation from solution.
A drop in pressure or temperature is a primary cause.
A change in pH or super saturation can also cause minerals to come out of solution.
There is some evidence that an extreme electric charge change can cause deposition of metals from solution.
With gold in particular sequestering of free chlorine atoms can cause a pregnant solution to drop gold.
From what I have read, the gold in solution is a compound, usually a chloride. In order to trick the gold into returning to a solid element you need to introduce some element that the chlorine world rather be with than the gold.
Depends on what the solution is...
Precipitation (ion replacment) occurs when an low PH solution will drop one metal ion to attack another more active metal ion
Metallic ions can also precipitate due to gravity, evaporation, pressure or electrolysis
Some very interesting comments as related to a molten slurry of super heated, super pressurized very dense molten solution of minerals being pushed up through weak spots in the earths crust from an equally hot pressurized chamber in the bowels of the very planet we stand upon.
At some point in the solutions movement it reaches its Zenith of travel and for various reasons it slows, stops and begins to change from a super heated solution to a solid and somewhere in that metamorphosis from a liquid to a solid several groups of sciences and physics cause it to do something very special. Something can be produced that drives mankind to be just a bubble off of level in its desire to have this substance, a unique yellow metal.
Time for one of Lanny's poignant Poem's!..............63bkpkr
Before I attempt to answer your rather vague question, I need to ask a few myself. Are you referring to how gold precipitates from a natural hydrothermal solution to make what is referred to as “Lode Gold”, or are you referring to a solution made while recovering or refining gold?
How about "how gold precipitates from a natural hydrothermal solution to make what is referred to as Lode Gold”. If your trying to find something it would be wise to figure out how it comes to be.
Thoughts from the masses might enlighten everyone more. johnnysau