What Does Natural Gold Look Like?
I'd like to get this post out of the way before I finish my two-part series on lesser known minerals and gold. I know the title of this post seems a bit nonsensical to those of us who've been at this gold prospecting and mining thing for a while now. But I am writing this in response to a comment (actually a question) from a reader who wants to know, so let's get at it.
Here is the reader's comment or query:
"I would really appreciate you guys publishing something of what raw gold looks like...meaning is there ever a time that gold is covered with something and you have to remove whatever build up to be able to see that it's even gold? Or the yellow is will always be visible when it comes to gold finding. Say for instance rubies or emeralds...you usually have to take off the layer of black to notice that it is a ruby. Are there any examples of what gold would look like before it is that golden color?"
First off, as I said in my comment reply to this query, it isn't "you guys" writing and publishing this blog. It's just little ol' me and it's been that way for 11 years now. Just so ya know.
Getting to the heart of the matter here it's obvious by the reader's statement or question that he (or she) hasn't seen much, if any gold, in its natural state as placer or lode. Were this untrue, the reader wouldn't be posing this query at all. That's not a put down, just a statement of fact. We all start this mining and prospecting thing as novices or greenhorns and learn as we go. So my answer here is that gold is gold and is immediately recognizable out in the field 99.9% of the time be it placer or free-milling lode gold. In other words, there's no mistaking gold as being gold. You veteran miners and old timers know it and I know it.
(There's no mistaking the real deal.)
What Gold Is
Gold has an even yellow or golden luster to it and will not sparkle or flash under direct sunlight or when viewed under direct artificial light, unlike its "fool's gold" counterparts pyrite and mica. Looking at a piece of natural gold is akin to looking at a bit of sunlight...there is a richness or sheen to it that's unmistakable to those in the know. And unlike pyrite or mica, gold is malleable (soft) and not brittle. It can't be broken or shattered like those forms of "fool's gold." Hit a piece of gold with a hammer and it will flatten out. Strike a piece of pyrite or mica with a hammer and it will shatter into hundreds of pieces or even a fine dust. Gold is also very dense and heavy (pyrite and mica are not) with a specific gravity of 19.2. This means it is nearly 20 times heavier than water which is why most gold ends up resting at the bottom of your gold pan after all the other larger rocks and gravel have been washed away. This is also why placer gold tends to seek its greatest depth (bedrock) in running streams and even in dry washes or gullies over time. The yellow metal just keeps working its way ever downward, especially those nuggets and coarse pieces. Gold is impervious to most acids or solutions applied to it except aqua regia, which is a solution composed of hydrochloric and nitric acids. Gold has been deemed a precious metal as long as written history has been around and even before that time. It doesn't oxidize or tarnish, it doesn't degrade over time, and it remains as pure and lustrous as the day it was mined, minted into coins, or worked into jewelry. Just like the universe at large, gold is eternal and everlasting.
No Such Thing
So yes, gold will nearly always be "golden" or have that glowing, yellow luster to it come rain or shine, or whether it's been mined in a stream or wash or from a free-milling vein or ledge. The only times I have come across placer gold that had a "covering" on it was when I recovered it as amalgam (very common in the California Motherlode Region) or, in certain dry placer areas where it had an uneven blackish coating of so-called "desert varnish" or even manganese on it. Amalgam is simply gold bonded together or covered with mercury. It will have a dull grey or silverish look to it but it will hang back in your pan or sluice box just like any other piece of yellow gold. In dry gold or desert areas placer gold will often have a coating of "caliche" or "desert cement" on it which will give it a dusty, dirty look that has to be washed or broken off. However, once this is done, that desert gold will shine just as brightly in the sunlight as a piece of placer gold taken from a running stream. Gold can also be orangish-yellow, pink, or a more silverish color depending on the amount of natural alloys in it. For instance, the more orange or reddish a piece of gold, the more copper or iron it will contain. The lighter and more silverish its color, the more silver it contains. In nature, there is no such thing as "pure gold." Both placer gold and lode gold are always "contaminated" with certain alloys which reduce gold's fineness or purity value. The only pure gold around are those gold bars and rounds stamped .999 fine gold. Even your gold coins or gold jewelry aren't pure gold. They contain varying amounts of alloys in them so they hold up better to wear and tear.
(Amalgam...in this case fine placer gold bonded with mercury.)
(A chunk of caliche or "desert cement." Sometimes placer gold in desert or dry areas will be coated this way.)
(Note that some of these Arizona nuggets are reddish-orange. This means they contain more copper or iron as alloy.)
In truth, once you find or recover gold in the field (whether that be a stream, wash, or free-milling vein) there is ABSOLUTELY NO MISTAKING it as being gold. If you're unsure of yourself, take that piece and rub it across a dark-colored rock. If it streaks a yellow, golden color what you have in your hot little hand is the real deal...the yellow metal we all prize so highly. If what you hold in your hand streaks black, or grey, or any other color other than that golden yellow, you haven't found your personal Motherlode my friend. This "streak" test is one of the simplest and easiest ways to determine if you're holding gold, barring the fact you have never seen natural gold before or have any idea what it really looks like. By the way, streak test kits are available from many sources. Alternately, bring along a piece of tile and use the rough side to streak test your finds in the field. Moving on, I can't speak to rubies or emeralds since I have no experience mining for them nor have I come across them other than in jewelry pieces or as specimens. In my personal prospecting and mining experience (40 years' worth) I have come across no coverings or coatings that would hide natural gold from your eyes, other than those things I've already mentioned.
(A black or blackish green streak? Pyrite my friends, or "fool's gold.)
(Streak tests from left to right: silver, copper, natural gold nugget, 10K jewelry, 14K jewelry. Gold always streaks gold!)
That's about it as far as answering this reader's comments or query (take your pick). If any other readers want to kick in their two-cents' worth feel free to do so by commenting at the bottom of this post. One thing I'd like to add here for all readers is this point: the comments section of each post is for comments...not questions. There's a difference between the two. If you have a question use my contact e-mail which is the right place for queries. Let's keep the comments section for comments, OK? Thanks.
To sum things up...gold look likes gold. That's the bottom line my friend...
(c) Jim Rocha 2019
Questions? E-mail me at firstname.lastname@example.org