Eighty kilometers west of Guadalajara Mexico lies a quiet town called Magdalena. The surrounding valley is peppered with small Mexican privately owned Opal mines. These mines are open pit mines where opal is painstakenly hammered out of the hard rock rhyolite matrix.
The Magdalena mines produce three types of opal. The jelly opal is in an orange to red crystal with color display of blue, red, green, yellow and orange. The cherry or fire opal is clear yellow to deep red with very little play of color. The third type is the clear blue opal with play of color that we call blue ice. The opal is cut and polished into free forms, cabochons and facetted gemstone. The opal from the Magdalena area is very stable and very rarely crazes or cracks with drying. Commonly there is a sick area in the opal that looks just like a small egg inside. These egg bearing opals are highly regarded in Asia as good luck pieces.
The mining process is extremely tedious and demanding hard labor. The large rocks are broken into smaller rocks with a sledge hammer. These rocks are further broken with a miner’s hammer or chisel. Each piece of rock that contains opal is separated into 5 gallon buckets. The opal crystal is then sawn from the matrix and finally cut and polished. Some of the opal is left in the surrounding matrix and cut and polished in that form. Large jelly opal over 350 carats in the rough form are found very rarely. These opals are usually cut and polished into a free form to conserve weight. Prices vary from $50 to $400 a carat for the various forms of Mexican opal.