Gold, Quartz & Chalcedony—Part II
November 2011 by W. Dan HauselThe specific gravity of chalcedony is 2.58 to 2.64. This is slightly lower than coarsely crystalline quartz because of slight porosity in chalcedony. Being so light, it will easily wash out of a gold pan.
It is a gemstone, and yet it is also closely associated with many types of metal ores. It's valuable itself but often points toward other valuable minerals—that is certainly something prospectors want to know more about!
The biggest obstacle is that like many streams on the Kenai Peninsula, high water during the summer months from snow melt and rain can make dredging nearly impossible. The best dredging is in the colder months of the year.
Apart from the hard rock mines, there are abundant gold-bearing placers, especially in the areas in and around Oriental Wash.
Prospectors who specialize in electronic detecting for nuggets in desert areas are especially interested in this type of deposit, as it yields nuggets that are close to the surface of the ground...
The other distinguishing feature of calcite has to do with its chemistry. Geologists sometimes take a small bottle of dilute hydrochloric acid out into the field with them because calcite reacts with acids to make a bubbly foam.
Kimberlite is very difficult for geologists to find, let alone prospectors and rock hounds. This is because kimberlite is rarely exposed on the surface and few people know how to identify the rock.
These deposits are very widespread across the planet. In fact, they are so extensive that something around 75% of all the gold ever mined comes from these types of deposits (if one includes the placer deposits that also formed from them).
The Bawl Mill • Legislative And Regulatory Update • Ask The Experts—Compensation for closed mining claim? • Ask The Experts—Inconsistent fire assays • Gold From Cemented Gravels • Evolution Of A Gold Prospect • Alaska to Target Rare-Earths • Minnesota Delays Decision on Mineral Leases • Alaska's Cripple Creek Mining District • The Gold Of Horseshoe Bend • Tyrie's Roadway Nugget • Melman on Gold & Silver