Agate: The Mineral With Rock-Bands

     Agate is a type of chalcedony that is known for its banding. Chalcedony is a variety of quartz in which tiny quartz crystals are packed closely together. Agate is a type of chalcedony in which there are layers of alternating shades or colors throughout the stone. If the agate is cut correctly these bands appear similar to the planet Saturn's rings. Agates are often found as amorphous lumps, rounded stones, or the linings of geodes. These geode-lining agates sometimes have quartz crystals of a slightly larger size at their centers. Agates are usually sliced to reveal their banding. No two agates are exactly alike, but most agates do exhibit similar patterns of banding. Different kinds of patterns have their own names, and I thought that it would be good to cover some of these. One type of agate has a pattern that reminds some people of the map of a hill fort; these are called fortification agates. Others have inclusions that look like green moss; they are called moss agates. A similar kind of agate has inclusions that look like the silhouette of trees and shrubs, which are called landscape agates. Agates that have individual, little swirls among the other larger swirls (somewhat like the planet Jupiter’s Red Spot) are called eye agates. An iridescent type of agate is known as fire agate. There are many other varieties of agate, but to describe them all would take the space of another blog!
     Agates are very popular as gemstones as they are hard enough to resist wear and scratching and also very beautiful. Agates are often cut en cabochon and set into mounts, but they are also made into cameos or simply polished as slabs. Agate has been a popular carving medium since ancient times (in a book about the Byzantine Empire I saw a goblet that was carved from agate) and the mineral is still used for carving today. Today agate is used to make…well, anything that you might want to carve. One carving that I have seen  in this age is a bookend. Slices of agate, which are translucent, are also used to make the coverings for decorative night-lights and fancy lampshades.
     Being a quartz-mineral agate is found worldwide throughout the Earth’s crust. Some of the best sources of agate include: Brazil, Uruguay, Germany, China, Egypt, and the coastline of Lake Superior.
     Agate is surely a fascinating mineral. Believe it or not agate is actually mentioned in the Bible! Agate is one of the twelve stones that God commanded the Israelite priests to wear on their breastplates (Exodus 28:19) God’s telling His people to use a piece of His creation in their worshiping Him is further proof that God is pleased with His creation!