The name comes from the “upala” sacrito which means precious stone and according to historical data, the opals from Mexico were used by the Aztec people for elaborating ornamental and ceremonial articles between the years 1200 and 1519. Knew to the opal with the name vitzitziltecpal or “stone Hummingbird”, referring to the resemblance of the iridescence of the gem with the plumage of the bird. One of the opals used by the Aztecs known worldwide with the name of the Aztec Sun God, is that it was found in a temple in the 16th century, and later formed part of the collection of gems of Hope. In 1881 it was sold to the Museum of Natural history in Chicago, to form part of the collection of gems Tiffany.

With the conquest of the Spaniards were lost up to Opal known localities, which, in 1840, don José María Siurab redescubrio deposits and began working the mines Santa María Iris, Hacienda Esmeralda. Other major deposits in hope Hacienda, La carbonera, including mine was discovered in 1855. Pioneer miners as Don Leonardo Godinez, Bulmaro Hernández and Joaquín Ontiveros Eugenio Ontiveros this last obtained the concession of the mine the eggshells, mine that had great production in those days. The region reached its peak in the year of 1969 as a result of the high demand of Opal abroad.

Institute of geology – Universidad Nacional Autónoma de Mexico
Rodolfo Corona Esquivel and Maria Elena Benavides Munoz
Bulletin of Mineralogy vch4, No.1 1989 p. 80-85

Magdalena land of opals

In the year of 1948 and 1950 are discovered the first mines in Magdalena, Jalisco and surrounding one of the first discovered mines was “The only one” discovered by Pascual González González in 1948 estimated date that tells us one of their children who survived by Mrs Elvira González, located in the foothills of the Tequila volcano but that initially belonged to the estate of huizizilapa in the municipality of Magdalena , Jalisco., later the mines of San Simón, which was discovered in the year of 1958 by Mr. Gabriel Rubio Galindo, who was dedicated to making charcoal were discovered and which to remove a rock that ordered him to make the oven and burn or prepare the coal is encuentara a stone that shone and which was realized it was an Opal , so selling the stone to be found. Work the mines some time and stated that it was opals “galore” and is said that filling a wheelbarrow of Opal crystals per week, its value of opals is unknown but a stone at that time could not be more expensive thousand five hundred or thousand dollars, estimated a top cost but is unaware of the real value of the stones. Poesteriormente there were other mines such as: La Estancia, La Mora, El Huaxical, Las Latille, Las Cruces, San Martin, La Pata de Gallo, the Hostotipaquillo and mine also in the mountains of El Salvador municipality of Tequila were discovered several mines as: La Perla, El Cobano discovered in 1970 this according to a miner to work awhile in these mines Mr. Jose Gutierrez Villalobos who was born in 1958 and today is mine craftsman resins with opal and Carver, also arise other mines from the same date as: Las Azucenas, La Linda, El Verde, El Ventarrón, La Camelia, Las Crucitas and La Falda, all these mines were discovered and exploited and it was so in the years of 1965 – 1975 took place in the region the opal fever. Says that opals came in such quantity that they were sold by sacks and that persons who were engaged in the opals are counted by thousands says people who lived that time of prosperity, yet there are many people who lived through those times and is very interesting to hear their stories and their stories of what was a day Opal fever.

CUVALLES, Centre Univesitario de los Valles, Ameca, Jalisco
July, 2009; Volume 1: Magdalena famous land of Opal.
Gabriela Romero Mata, Maria de Jesus Romero kills, Juan Jose Virgin Alatorre

Composition of Opal

Chemical formula: SiO2-NH2O
Class: silicates
Subclass: Tectosilicates
Group: silica
Etymology: Comes from the Sanskrit “upar it” which means gem or gemstone.
Crystallography: Opal is amorphous but precious varieties contain bagging ordered silica spheres.
Color: Colorless, white tones pale of yellow, red, Brown, green, gray and blue. Sometimes it looks milky and opalescent, sometimes iridescent. Precious opal is characterized by the intense brightness of its colors being white body in general. The fire opal is a variety with intense Orange reflections.
Luster: Vitreous rather resinous.
Hardness: 5.5
Density: 2.65 g/cm3
Optics: Index of refraction between 1.44 and 1.46

Others: Conchoidal fracture. Some opals especially the Hialita (colourless, transparent variety) have yellow-greenish fluorescence under ultraviolet light.
Chemistry: It is pure silica in presence of water between 4-9%, can reach up to 20%.

Genesis: Opal is a gel product of deposition of hot springs, found in nodules concrecionar them in some sedimentary rocks. Form the skeleton of some animals and plants, often being the fosilizador element of the latter.

Formation of opals: Opals are the result of weather, as are formed over millions of years, while the silica and volcanic rock layers overlap, catching passing tiny spheres of water and oxygen. Therefore these areas that opals, in a diffraction effect, partitioned its unique colour and luminosity, being fundamental to determine its quality. The most beautiful is one largest Opal it will be its quality.