Gemology is simply the study of gemstones. It's a branch of a geoscience but also a branch of mineralogy. Many jewelers are often also gemologers, which helps the identify and evaluate gemstone. Field gemology is simply an extension of a field gemolology to the field. Most field gemologists travel to exotic locations to locate and study precious minerals. Very popular locations are Kenya, India, Sri Lanka and even Colombia.
A gem, also known as a precious stone, is polished and cut from a piece of attractive mineral to make accessories such as jewelry. There are also rocks that aren't minerals that are considered gems as well. The rarer the stone and the more exquisite the color, the higher the value. As well as this, other factors determine its value including clarity, color zoning, star effects (asteria) and cut. It also depends on how it's marketed, if there is a huge desire from the market and the popularity of the stone itself. The most popular gems, which are found in a fair few countries including India, that are constituted as precious are diamonds, rubies, emeralds and sapphires. Morro bay museum of natural history has numerous gemstones on display, it has one of the most extensive gem and precious mineral collections in the world, it's also a great travel destination for both kids and adults!