Gems from the Safe

Geoscience Australia

Explore our most valuable treasures!  

This two tonne fire resistant safe has been in existence for over 70 years. The drawers inside were custom built for the purpose of storing valuable gems, minerals and meteorites.

The safe contains our most valuable specimens which were sourced from field collection, purchasing, donation, as well as a significant number which were gifted to the National Museum of Australia. In total there are 15 000 specimens in the collection from all over the world, with the first to be accessioned in 1929.

The collection supported geologists who were undertaking fieldwork into the establishment and development of Australia’s capital city, Canberra. As work programs expanded into other areas across the country, together with changing priorities such as the search for strategic metals post WWII, the collection also grew into the museum that it is today.

This specimen of pyrosmalite (Mn) is regarded as the best of its type in the world due to the large size (up to 1 cm) of crystal clusters on calcite.

It was purchased in 1963 from Albert R. (Floss) Campbell who was a collector of fine minerals. It is the most valuable specimen (monetarily) in the Geoscience Australia National Mineral Collection.

This specimen comes from the famous Australian gold locality of Kalgoorlie, Western Australia. Gold was first discovered in the area around the late 19th century and is is now home to the Super Pit open-cut mine.

Did you know that opals are Australia's national gemstone?

There are a number of opal shells in the collection that were found at Coober Pedy, South Australia. This world class opal region was once a marine environment during the Cretaceous (~146-65 million years ago) period when the shell was deposited and covered by sediment. During the Miocene (~23-5 million years ago) period, the original shell was replaced by opal.

This ruby (corundum) section in amphibolite was sent to Geoscience Australia in the 1960s by Hillside Properties for analysis work. In appreciation, the company donated a number of specimens to the collection.

Corundum is a crystalline aluminium oxide that comes in many varieties. For example, gem quality red corundum is referred to as ruby whilst blue varieties are sapphires.

Topaz is used for gem and jewellery purposes and comes in many different colours. It has a high refractive index therefore when faceted makes a very bright jewel. Colourless specimens are generally the most common.

Aspen in Colorado (USA) has produced large amounts of silver over the years including one of the worlds largest nuggets. This specimen from Aspen demonstrates the fineness and branch like structure that is typical for native silver.

The Roman's referred to silver as Argentum and hence its chemical element abbreviation is Ag.

Gem quality rhodonite is quite rare. Some of the finer specimens such as this have come from the famous Broken Hill lead-silver-zinc deposit which was one of the largest such deposits ever discovered. It produced over 300 minerals including the manganese-rich rhodonite. This is one of 6 pieces that have been faceted into fine jewels in the collection.

Dioptase is a popular mineral with collectors because of its rich green and blue colour. Named in 1797 by Hauy, dioptase means "through" and 'to see' in reference to the visibility of internal cleavage planes.

Due to modern processing techniques at mine sites, it is rare to find a diamond still in its host rock, kimberlite, such as this. Diamonds form within the Earth's mantle at great depth and pressure compared to many other minerals. They are transported to the crust via the kimberlite host magma.

Heulandite is a type of zeolite. This zeolite is from cavities in volcanic rocks of the Warrumbungle mountain range, an area which contains some of the best zeolites in Australia. Some of the cavities discovered at the site were tens of metres in length.

Anglesite is a secondary lead sulphate mineral ranging in colours, in this case the very rare green crystalline mineral. Named after the type locality, Parys Mine on the island of Anglesey in Wales, U.K.

Watermelon tourmaline is so named for the striking balance of green on the outer rims of the mineral with a white inner layer followed by variations of orange-red or pink.

Amazonite is more typically coloured green than the blue variety here. It is thought that the colour is derived from an elevated lead content. Named after the Amazon River in Brazil, amazonite is a microline feldspar.

Pictured here is a set of beautiful azurite crystals. Azurite is a copper mineral. The name comes from the Persian word lazhward meaning 'blue' in reference to the colour.

Azurite, over very long time periods, oxidises to malachite (green mineral) as you can see in this specimen. This weathering process makes malachite a pseudomorph of azurite.

Did you know the mineral chrysocolla (another secondary copper mineral) can pseudomorph from malachite, after azurite, known as a double pseudomorph?

Calcite is a common mineral but what makes this specimen valuable is its large size, shape and colour.

Rhodochrosite is a manganese mineral which when transparent, raspberry coloured and in crystal form is rare and commands high prices by collectors. It is the national gemstone of Argentina.

A true gemstone, this golden yellow variety of beryl is referred to as heliodor. Note: emeralds are the green variety of beryl and aquamarine is a blue-green variety of beryl when gem quality.

Known from only a handful of localities, such as the Black Pine mine, Montana, USA, the copper-zinc mineral veszelyite is an extremely rare gem with crystal sizes usually less than 10 mm.

Brazilianite is typically found in granite pegmatites and is named by Frederick Harvey Pough and Edward Porter Henderson in 1945 for the type locality country, Brazil, where it was first found.

Some of the finest specimens of stolzite come from the Broken Hill lode in Australia. A lead tungstate with the formula Pb(WO4) it is a rare secondary mineral in the oxidized zones of hydrothermal deposits.

There is great variety in the colours of smithsonite specimens held in the Geoscience Australia collection. The following images demonstrate this for the zinc carbonate mineral.

Pyromorphite comes in a variety of colours, yellow, green, brown, grey, and colourless. It is a secondary lead mineral with barrel-shaped hexagonal prisms, in clusters often lining cavities.

Credits: Story

The National Mineral and Commonwealth Paleontological Collection, Geoscience Australia and The National Museum of Australia Mineral Collections (specimens)

Chris Fitzgerald (photography)

Steven Petkovski and Peter Butler (text/editing)

Dave Champion (scientific review)

Marie Lake (safe image editing)

Copyright for content: http://www.ga.gov.au/copyright

Credits: All media
The story featured may in some cases have been created by an independent third party and may not always represent the views of the institutions, listed below, who have supplied the content.
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