"Child finds precious stone in bucket of gravel!" Maybe you've seen headlines like that and wished you could find gemstones yourself. There is one kind you can find easily, if you know where to look. Finding semi-precious agates may never make you rich, but agate-hunting can be a rewarding and colorful hobby.
• What Agates Are
Agates are transparent stones made up of quartz and a number of colored minerals. Silica - the same mineral that sand and computer chips are made of - dissolved in water creeps into small spaces in volcanic rock. When the silica is left behind it crystallizes. Slow crystallization results in large crystals that are valuable as gems: amethyst, rose quartz, and rock crystal are examples. Fast crystallization forms "massy," glass-like quartz such as agate, jasper, tiger-eye, aventurine, and onyx.
• How To Find Agates
Deposits of agate are usually found in igneous rock and are washed free by water erosion. Any place where rivers, streams, or the ocean wear away at volcanic rock you can often find agates: pebble-strewn beaches, gravel beds along rivers, rocky stream bottoms. Rocky shores where seashell hunting is a disappointment will often yield agates instead.
Patience is the key in agate hunting. Most hunters stroll slowly through patches of gravel, watching for a flash of color among the rocks. In strong sunlight, the clear agates will stand out against darker rocks. Hunting among wet pebbles is usually more productive, since wetness makes the colors brighter and the clear stones more obvious. On the beach, outgoing tides reveal freshly-churned gravel beds ready to be picked over.
Agate grounds along the west coast are often unpredictable, yielding a rich supply one year and none the next. Local rock shops will usually be happy to tell you where to look. For safety's sake, never turn your back on the sea. "Sneaker" waves can be extremely dangerous. Do not be tempted to climb cliffs and bluffs in search of agate veins. Climbing ocean cliffs is dangerous, environmentally unsound, and may involve trespassing.
• Types Of Agates
• Carnelians are most common. They are transparent stones which may be rich orange-red, yellow, white, or brown, with little or no banding. The lightest forms are called Sard.
• Moonstones are bright, milky white, clear stones. Moonstones with rainbows in them are called iris agates.
• Ribbon agate has straight bands of color caused by different mineral impurities as the silica was deposited. If the bands are wavy, the stone is called fortification agate because the patterns often resemble medieval hill fortifications seen from above.
• Picture agates are any kind of agate that have a mineral deposit that forms a figure. These are prized for jewelry.
• Cloud agates, also called blue agates, are mottled with blue-black, blue, and milky colors. True blue agates are highly prized.
• Moss agates don't really have moss in them. Mineral deposits form the branched, mossy patterns seen in these stones. Many form tree-like pictures, and are called landscape agates.
• Jasper is another massy quartz stone found alongside agates. It is not transparent, but is often brilliantly colored. Jasper comes in red, yellow, and green.
• Bloodstone is a type of dark green jasper with red spots. It is fairly rare. Bloodstone is sometimes called Heliotrope.
• Petrified wood is formed when agate or jasper deposits replace wood. It is a type of fossil.
• What To Do With Agates
Because agate is a hard stone, it can be tumbled to a high polish. Inexpensive rock tumblers can be found at most hobby shops. It can take up to a month to polish rocks, so be patient. Hobby shops or craft shops may also sell jewelry "findings" (earring bases, key chains, etc.) to turn your tumbled stones into jewelry. Polished agates can also be piled into fancy jars for decoration, placed around cacti and small plants in dish gardens, or used in aquariums.
Keep in mind that agates are a mineral deposit, so by no means are a renewable resource. Take only what you will use, and leave the rest for others to enjoy.