Identify Unpolished
Agates
Agates are semiprecious gems that can be found all over the world. Throughout history, they have been valued as stones of impressive beauty and charm. Most people recognize agate as a highly polished, banded stone, but recognizing unpolished agate on a lake or in a freshly plowed field is a little tougher. Identifying unpolished agate is something that any amateur geologist can learn to do.
Instructions
1. Look for translucence in the stone. If the stone has been broken and you can see telltale traces of a quartzlike mineral along with the red, brown and orange color that comes with many types of agate, there is a good chance that you have an unpolished agate.
2. Determine whether there is banding. If the rocky exterior of the stone is broken or worn away, look for banding, which occurs in most types of agate. The banding is a factor that is sought by many collectors and jewelry makers, states the Keweenaw Traveler website.
3. Measure the stone. In most cases, the average agate is less than 3 inches in diameter.
4. Heft the stone. Most agate pebbles feel heavier than they look due to their dense composition. You may wish to compare them with other stones that are lying close by.
5. Look for a pit-marked surface on the rough stone. Agates can be formed in igneous rock, and they can also be surrounded by softer rock that has since eroded away. Both of these features can leave the agate with some pitting.
6. Feel for any waxiness in the revealed stone. When you see a crack in the stone or a place where the rocky exterior has worn away, slide your fingers across it. Waxiness is a sign that you might have an agate.
7. Look for conchoidal fractures, which are irregular fractures that occur in fine-grained materials such as glass and obsidian. These fractures are often curved, with a wavelike pattern, and they result in a very irregular profile to the rock itself. Agates are prone to conchoidal fractures, and seeing a rock with a distinct profile can alert you to an agate's presence.
Tags: unpolished agate, conchoidal fractures, Identify Unpolished, Identify Unpolished Agates, rocky exterior, types agate, Unpolished Agates
