Opal Deposits outside Australia Mexico Discovered in 1835 but probably have been known to the Aztec. Source of much Fire and Cherry Opal and some fine White Opal. Areas near Mexico City produce from rhyolitic volcanic rock. esign/gem_notes/Opal/ Jewellery pendant with Mexican opal

Opal mining area with mine tailings near Queretaro, Mexico. Access by dirt-road; the area is a semi-arid climate zone with numerous cactus plants.

View down into a deep shaft of the Guacamaja mine. This type of mine is typical of the simple open-pit quarries in Queretaro. The walls can be up to 70m high.

Miners entering the active mining area Tunnel leading to the next underground opal deposit.

Miners inspecting some opal veins Miner working on rock containing opal. The broken boulders are stacked in a pile to be broken down by hand into pieces 5 cm or less to improve recovery of gem- quality material.

One can easily see the very thinly bedded rhyolite lava flows in the piece. The opal occurs as secondary filling in cavities caused by gas in the lava flow. Here the miner is hammering on a rock which was dynamited from the quarry wall. The opal is trapped in the before mentioned cavities completely but occasionally it is found as loose nodules in the open spaces. These loose nodules, which may be "as large as a hen's egg", are generally the highest quality material.

Pieces of rough Mexican opal Spectacular carved piece of opal

Entrance to the Iris mine. After many years of operation the mine was closed in It then reopened several times and closed again in It was the most productive mine in the Queretaro region. Several miners were still strolling around showing off their wares in typical glass vials. But most of the opal - as they said - was material for the "gringos": cheap fire opal.

Numerous pieces of rough fire opalSelection of carved Mexican opal Carved fine Mexican opal Mexican opal in rhyolite

Interesting carved Mexican opal Better quality Mexican opal usually has a reddish- orange base colour with lighter to darker shades. Other base colours are possible.

Mexican opal is typically an orange crystal. If it does not show any play of colour it is inappropriately called fire opal and usually faceted. These stones sometimes are easily confused with orange agate. Superb pieces of Mexican opal Black Fire Jelly

Very nice top quality Mexican opal cabochons. The rough for these pieces has been stored initially for five years before cutting. An opal dealer recently reported that they had problems with material coming from a shaft just 20 m from the original mine where the material used to be durable. The opals broke into pieces when polished. Mexican opal in rhyolite

Precious Opals in Canada The Klinker Opal Deposit, located near Vernon, B.C.was discovered on October 14, In 1994, Okanagan Opal Inc. has explored and developed the Klinker Property to the stage where adequate reserves of opal have been identified to support small scale mine production. Opal from the Klinker Deposit is classified as "boulder opal". This material exhibits variable base colours ranging from transparent, water clear to clear amber to translucent /opaque white to dark brown and exhibiting a variable intensity "play of colour" in a flash to broad flash pattern. 3_opals.html

What better way to spend a day than to try your luck at finding your own opals? The Klinker Opal Property is located in the mountains approximately 40 kilometres by road from Vernon, BC and is situated at an elevation of about 1500 metres above sea level. DIG YOUR OWN OPALS!

Capped boulder opal doublet pendant. Natural solid semi-crystal opal pendant.

Black-backed Doublets Boulder Opal Doublets Opal from Okaganan Deposits, B.C.

Contra luz opal from Oregon. Oregon.--During 1988, West Coast Gemstones, Inc., began mining and marketing a variety of very fine-quality opals from Opal Butte in Morrow County, OR. The varieties produced includes hyalite, rainbow, contra luz, hydrophane, crystal, fire, blue, and dendritic. Exquisite stones as large as 315 carats have been cut from contra luz rough from this deposit. United States Most important area is in northern Nevada (Virgin Valley); opal here replaces petrified wood in volcanic ash. Has extremely high water content, get beautiful black opal with red flashes. Is notorious for dehydrating with time, however, causing cracking, crazing and making it less marketable.

Louisiana.--The reported precious opal from Louisiana is a sandstone/quartzite with precious opal cement and matrix. It has blue or purple play of color. The material could be cut into cabochons for jewelry and other items of interest. To date, most of the material has been cut into large (over 2-inches in diameter) gemstone spheres. Nevada.--Nevada is known for precious opal from Virgin Valley. The first discovery of precious opal in the Virgin Valley area was in 1905 or Since then a significant quantity of the highly prized opal has been recovered. Virgin Valley opal is comparable to any in the world for its vivid play of color and in terms of the size of material available.

Opal from Royal Peacock mine, Virgin Valley, Nevada.

Hondourus VAR: opalitic sandstone Hondourus Location : Lempira-Gracios a Dios Host rock : Basalts and trachytes Production : Commercial-minor

Location : Piaui Host rock : Sandstone, underlain by dolerite. Production : Commercial-minor Brazil

Gem & Gemmology, Summer 1996: Opal from Shewa Province, Ethiopia Ethiopia