Red Lead Crocoite Mine Reopened!

Write By: tmmadmin Published In: Classic Mineral Localities Created Date: 2014-12-14 Hits: 4039 Comment: 0


Crocoite specimen found in the 1960s

In October, 2012 the Red Lead Mine in Dundas, Tasmania was reopened for specimen mining by Collector's Edge minerals and mine owner Shane Dohnt. In the first few months of operation, high quality specimens were found, featuring brilliant color, superior luster, and outstanding translucency. The miners have high hopes for finding world-class specimens similar to those recovered long ago, which sported crystals to over 6" in length. Many feel these crocoites are the best in the world for gemminess and quality.


Crocoite crystals collected in the 1970s

In the Red Lead Mine, the primary ore was altered gossans which occur as veins and pods in the sedimentary host rock. Crocoite crystals are found in the vugs and in joints in the veins. Unlike the nearby Adelaide Mine, crocoite from Red Lead is rarely found in hollow "jackstraw" crystals.

HISTORY
The Red Lead Mine was discovered in 1890 by Thomas Page, of Zeehan, and was worked intermittently for approximately four years as the Dundas Extended Mine. This mine was the first recorded occurrence of the mineral crocoite in the Dundas mining district. Specimens far surpassed those from the original Russian locality in terms of crystallographic perfection and size. This created an uproar amongst mineralogists at the turn of the 20th century, as mineral museums and collectors scrambled to purchase the best examples for their collections. During this time an 80 foot shaft was sunk to intersect the lode, and a connecting adit was driven 300 feet to intersect it. Despite extensive tunneling on this lode and several smaller lodes, no un-oxidized ore was found, and the mine was abandoned with no production recorded.


Harvard University specimen collected in the 1970s

In 1902 the mine reopened and was worked for two years for ferromanganese. During this time over 2400 tons of flux was trucked to the Zeehan smelters for its silver content (only about five grams per ton). During this time, large quantities of crocoite were undoubtedly sent to the smelters. As part of this operation, miners dug a connecting adit from the base of the 80 foot shaft to an area about 100 meters to the east where the lode was about two meters wide.


Surface workings at the Red Lead Mine in 2004

The first mention of the name "Red Lead Mine" was in a geological report on the district issued in 1925. Apparently work was performed in the interim, because the report mentions adits high on the eastern side of the hill which postdate the flux mining period. After that, the mine lay idle until the mid 1970's, when various miners worked the area for specimen crocoite. Using heavy digging equipment, they opened a large cut in the hill in the vicinity of the lodes. Over the next 30 years this area was expanded, leaving a 7½ acre open cut to a depth of twenty meters below the top of the hill.


Mine owner Shane Dohnt gestures at a tunnel opened from the top using heavy equiment

In 1986, Shane Dohnt purchased the mine and has been working it ever since. Initially he continued work in the open cut, then more recently developed a plan to access the load via old tunnels. In the late 1990's, he discovered an open water-course in an underground tunnel that was up to fifteen cm wide. Scattered through it were pockets containing single crystals to 15 cm, some complexly terminated, while others were contact terminated. On the walls were huge crystals to 30 x 3 cm that were almost completely fractured. Unfortunately, hardly a single piece was recovered. Most recently, Dohnt's very promising underground work at the Red Lead Mine has been severely hampered by collapses in the tunnels driven through unstable gossan material.

RECENT WORKINGS


Mini loader hauling waste rock

The old mine tunnels were in very poor condition, due to collapse and flooding since the 1970s. A dam, which had formed near the main entrance, was removed, and water reportedly poured out of the old mine like a river. Miners then examined the tunnels, attempting to identify zones with the greatest promise, and created a detailed geological map. Mine tunnels, which were narrow and short, cut through the fragile gossan matrix, but these were prone to collapse. A narrow micro-mining machine was purchased, and its augers, rock breakers and loader were put to use widening and enlarging the tunnels. Waste rock was loaded into self-propelled carts, which hauled the debris out of the mine. This equipment allowed miners to advance about 15 feet per day. Then, to ensure safe operations, timbering and full wooden shoring was installed in the tunnels, along with strong wire mesh. A complete ventilation system was also put in, and the equipment burned biodiesel fuel to reduce harmful emissions.


Looking out from insdie the enlarged entrance tunnel

As mining proceeded, the first pocket was encountered on a shaft off of the main drift. . It was named the "Stop the Bleeding Pocket," referring to the outlay of funds needed to mine here. It was about 24" x 12" x 4", and contained some good quality crystals which helped pay for ongoing work. In September 2013 a second pocket was encountered, which was about 6.5' long. This pocket appeared to be connected overhead to a surface fissure which was mined from the surface in the open cut. If so, there was another 50' of fissure still waiting to be explored.


View of overhead shoring in a tunnel

Extracting specimens without damaging the crystals is very difficult, due to the fragility of crocoite crystals. When high quality specimens are found, a diamond chainsaw is used to cut the specimens out with the least possible vibration. Lower quality pieces are taken out with small, hand-held jackhammers. All of the specimens are crated and shipped to Colorado for trimming and cleaning, and eventually for sale.

The whole mineral collecting community is hoping to see new world-class specimens from the Red Lead Mine. I think everyone is rooting for Brian Lees to make a great success of his mining efforts here, perhaps on a scale comparable to what he accomplished at the Sweet Home Mine. Although no fantastic, world class speicmens have been found yet, who knows what treasures remain hidden in this world-famous mine?


Collector's Edge display case at the 2014 Tucson Show


Another Collector's Edge display case at the 2014 Tucson Show


A 5" x 4" specimen from the new mining ($4,500)


A 4" specimen from the new mining ($1,500)

© Eric Greene 2014

Leave A Comment

Captcha