Gold's Mineral Indicators (Part 1)
(Mineral identification is more important than you may think.)
Knowing what minerals are associated with placer and lode gold (vein or reef) deposits is necessary knowledge for small-scale gold miners and prospectors whatever their individual levels of experience. In this series of posts I'll be listing and describing some of these gold-related minerals, especially those that are most directly associated with placer or lode gold.
Placer Deposit Minerals
Quartz: I actually hate using quartz or quartzitic rocks as examples since quite a few folks tend to get fixated on quartz as the only "true path" to placer or lode gold. Quartz minerals are important to gold...there's no doubt about that. But as I said before in Bedrock Dreams, quartz is NOT the only mineral indicator of the potential presence of gold. You newbies and less experienced folks need to get that through your heads lest you get a bad case of tunnel vision in this regard. In the majority of cases, quartz rocks or rocks containing quartz don't constitute the presence of gold of and by themselves unless they show the presence of some sort of alteration including the presence of sulfides, pyrites, tellurides, and so on. Since I don't want to repeat myself in the lode gold section, quartz is often associated with gold-bearing vein material where the local geology is conducive to mineralization. To sum things up, yes...the presence of small bits of quartz or quartizitic rocks in your gold pan can be positive mineral indicators, but they are never a sure thing when it comes to getting placer gold.
(There ain't a speck of gold in this "bull" quartz, as the old timers called it.)
(A piece of quartzitic gold ore showing mineralization/alteration.)
(Heavy black sands and placer gold.)
(Hematite specimen. What you find in your gold pan or sluice is a finely crushed version of this.)
(Close up of garnets in black sands.)
(c) Jim Rocha 2016
Questions? E-mail me at firstname.lastname@example.org