Element number 79 on the Periodic Table, also known by the letter code Au, has driven people to strange extremes over the years. During the gold rush, many prospectors abandoned homes and families in search of the gleaming metal. Fortunes were won and lost, and more than a few depraved and soulless acts were committed for its sake. It seems strange that a simple metal wields so much power over the human imagination. But attempts at objectivity often melt away after hefting a dense, yellow nugget in one's hand.
Gold has many properties that make it desirable, but when analyzed individually, none of them seem to merit all the fuss. The metal is one of only three which have a natural color other than grey or white, the other two being copper and cesium. Gold is extremely resistant to tarnishing and corrosion. In addition, pure gold is the most malleable of all metals—a single gram can be pounded into a thin sheet as large as one square meter. Gold is mentioned in many of the worlds oldest texts, from Egyptian hieroglyphs to the Old Testament.
In nature, gold usually occurs in its native state, as a metal. These deposits usually consist of small grains or microscopic particles of metallic gold embedded in solid rock. The surrounding rocks are often quartz or sulfide minerals such as pyrite. The native gold itself is usually an alloy containing around ten percent silver.
Most areas likely to harbor lode deposits of gold have been thoroughly explored and exploited. The chances of finding a new lode worth mining are slim indeed. Most future discoveries will probably be limited to those who use new technology to reassess areas know to produce gold in the past. At one time, prospecting for lode deposits was a relatively simple task. These days, however, most conspicious exposures and outcrops have already been examined. Modern prospectors must sample the broken rock in mine dumps and tailings, as well as workings inside mines where accessible. Lode gold is sometimes visible to the unaided eye, but more often detection requires collecting and chemically analyzing several pounds of rock.
A placer is any deposit of sand, gravel, or other natural material that has accumulated in a streambed, on a beach, or in residual alluvial deposits. Due to its high density, gold tends to gather and concentrate in placer deposits.
Gold is incredibly resistant to weathering and oxidation. As a result, nuggets and grains of gold become freed from captivity as their surrounding rock erodes away. Over the years, these small pieces of metal tumble down from their place of origin. Usually river water is responsible for transporting gold away from the original lode. During high-flow periods, when the rocks and gravel at the bottom of a stream move and shift, gold settles downward. It collects in depressions in the bedrock, underneath large boulders, and at the bottom of sand or gravel bars where the current slows.
Placer gold also occurs along intermittent streams and ephemeral channels such as desert washes and arroyos. Occasional flash floods and water flow perform the function of moving and concentrating the gold. Conventional placer mining requires a steady supply of water, so recovering gold from these types of dry deposits can be quite difficult and expensive.
Gold panning is the simplest and least-expensive method of recovering gold from placers. Panning involves using a shallow, flat-bottomed vessel to wash gold-bearing sand or gravel. As material is swirled around in the pan, gold will settle to the bottom and get trapped in a set of ridges across the sloping side of the pan. Gold panning is tedious, backbreaking labor. Furthermore, reliably separating gold by panning requires a great deal of practice.
According to the Utah Geological Survey (UGS), gold placers in Utah are usually associated with areas of igneous rock. Many of Utah's placer deposits consist of very fine-grained gold which is difficult to recover. In addition, many of these placers have been worked and reworked over the past 100 years, greatly reducing one's chance of finding large deposits. However, finding gold is still possible in many regions of the state. The list below, compiled by UGS, describes several places known to contain placer gold deposits.