John's New England Minerals and General Geology Blog: December 2016

TOURMALINE IN QUARTZ LOCALITY WALLANGRA NSW

Photo by Wwoofa via the Australian Lapidary Forum

This is a well-known mineral collecting locality in northern NSW, on the western edge of what is commonly called the New England region. Unfortunately it is a place I’ve never visited so I am depending on the descriptions of others.

The Inverell Tourism website has this to say:

“Wallangra Fossicking Area. Wallangra located north of Inverell has an area near the hall where you can hunt for Black Tourmaline in Quartz, once again this is a dry fossicking area. Contact Details: Wallangra Hall, Wallangra (65km north of Inverell) Ph: (02) 6728 8161.”

You may not find that particularly helpful. Knowing that the spot is near the Hall is good, but you also need to know that this is on the left hand side of the Yetman road. I’m sure you will find the place OK without ringing Wallangra.

The spot is open freely to fossickers. Please do the right thing and leave your mechanical diggers at home. As well as your specimens, take home all your rubbish and other people’s as well if you come across any.

There is a stack of information available on the Australian Lapidary Forum. I suggest you become a forum member so you can access it. Here. You can then contribute to the Forum by telling members about your visit to Wallangra.

I will point out at this stage that Wallangra and Wallangarra are quite different places. The latter is just across the NSW border into Queensland on the New England Highway.

This is an extract from the Inverell 1:250000 geological map. It shows that Wallangra is situated in an area marked Pg (Permian Granite, actually part of the Bundarra Suite).

The Australian Stratigraphic Units Database contains this definition of the “granites” of the Bundarra Suite:

“Coarse- to very coarse-grained, porphyritic and equigranular (biotite)-(muscovite)-(garnet)-(cordierite) granite and leucogranite; K-feldspar megacrysts abundant in places.” This is the host rock in which the Wallangra tourmaline in quartz bodies are found.

I have been unable to find any account of the detailed geology of the occurrence.

Mindat (here), however, regards the site as significant. Here is what a search on the location produces:

“Latitude & Longitude (WGS84):	29° 13' 54'' South , 150° 53' 4'' East
Latitude & Longitude (decimal):	-29.2316666667, 150.884444444

Located south of Texas, Qld.

Wallangra (in Northern New South Wales) was the site of a quarry, the area is now a designated Fossicking area. There is a quartz outcrop which contains tourmaline.

Mineral List: Anatase, Brookite, Muscovite, Quartz, Schorl,'Tourmaline'”

You will notice that the word ‘tourmaline’ is in quotes. This is because tourmaline is the name of a mineral family, rather than an individual mineral. In this case, the mineral is schorl – commonly called black tourmaline. If you want to read more about the tourmaline group, check this Mindat reference here.