Can a smoky quartz crystal have amethyst in it? Like a little purple there?
gold is usuallly found with the quartz deposits in the ground.
The field guide for Rocks and Mineral of North America is a very good resource for this topic!
Quartz is a common mineral that occurs in granitic magmas, sedimentary rocks, metamorphic rocks and in hydrothermal veins. You are probably referring to the hydrothermal quartz, why is sometimes associated with gold but others not. Again quartz can form at virtually any temperature, very low (100 C) to very high (500 C) in hydrothermal veins. Nevertheless, most gold deposits form at about 200 to 300 C, and usually close to 250 C. So, if the hydrothermal process was too hot it might have transported the gold (if there was enough H2S and Cl in the system), but gold precipitates at about 200 to 300C. If you have quartz of lower temperature, it probably have not gold. So in summary, it is a mixture of the temperature and the ligands (the compounds that transported the gold) of the fuids.
One variety, milky quartz is associated with gold. The geothermal conditions that produce milky quartz are associated with the uplifts that produce mountains that are likely to contain gold.
Well, let me see here. Gold is an uncommon metal and quartz is the most common mineral in the crust of the Earth. It could have something to do with that.
