Sand collector Tonny Brinkman has generously donated 3500 sands to Auckland Museum - and her decades of collecting show that you can explore the world without going far from home. As the motto of International Sand Collectors Society says: 'Discovering the World, Grain by Grain'.

'Discovering the World, Grain by Grain'

Tonny (Antonia) Brinkman was born in The Netherlands in 1924, came to New Zealand in 1963, and today lives in Henderson. She began collecting in 1977 and by collecting and swapping with others has a huge collection of not just sand, but also rocks and minerals. With the latter she won many prizes at rock and mineral shows. These are now disbursed to family, the Matakohe Kauri Museum, and some are in Auckland Museum’s Brinkman Collection.

Tonny clearly derived a lot of pleasure and gained great knowledge of other places by swapping with people from all over the world, learning about where the sand came from and why. Without the advantage of the internet it was mostly done via the postal system and use of the library. Some of the overseas collectors sent detailed maps and diagrams of exactly when and where the sand was collected. Unlike many collectors Tonny meticulously noted and recorded details of each sample which are labelled accordingly. This is what makes the Brinkman Collection scientifically valuable. Phew, so much work!

Thanks to the generous donation of Tonny, the Museum now has a huge collection of sands (over 3500) from Antarctica to Norway and from New Zealand to Australia, Africa and South America.

Sentiments for sediments

People who love sand are called arenophiles, from the Latin arena for sand or sandy area, such as the floor of the Colosseum in Rome (hence our use of the word today for sports facilities). A geologist who studies arenaceous sediment is called a sedimentologist.

What is sand?

To a geologist or sedimentologist sand is particulate material ranging in size from 0.063 to 2 millimetres in size. It can be derived from the weathering and erosion of any rock (igneous, metamorphic or sedimentary), or it could be a volcanic ash, or be derived from the breakdown of marine organisms (e.g. Coromandel beach shell sand), or is produced by microscopic animals and plants such as foraminifera (e.g. tropical beaches), or diatoms (e.g. fresh water lakes), or be chemical 'precipitates' (e.g. tropical oolites).

Natural processes will sort and concentrate sand-sized particles by size, density and durability giving rise to some unique and beautiful sands. For example the green olivine-rich sands of Hawaii, red garnet-rich sands of Southland, black magnetic iron oxide-rich sands along the West Coast of New Zealand or the golden quartz-rich desert sands of uniform grain size sorted by the wind in arid climates. Tonny's collection includes examples of all of these from a huge range of environments (deserts, beaches, rivers, lakes, volcanoes, submarine environments and human processing of materials). Probably the only place she doesn't have sand from is other parts of the solar system or the Universe!

Why is the collection important?

The aesthetic beauty of the sands aside, Tonny's collection has great untapped research potential. Firstly they are an archive of what a given area used to be like and can be used to document change or impacts. Those who study sedimentary rocks would find them useful palaeoenvironmental indicators since 'the present is a key to the past'. For example a sandstone may have an unusual grain-size distribution or mineralogy that can be matched to one of Tonny's samples. So the modern sand and its data could be used as an analogue to tell us what the environment was like when the ancient sediments were being deposited millions of years ago.

The samples could even be used forensically. Sand can stick to tyres and be found inside vehicles, footwear or clothing. Despite denials, matching the suspect sediment to Tonny's sand library might well tell us where someone had been recently - literally anywhere in the world. A similar technique was used to help convict some of the French agents responsible for the Rainbow Warrior bombing in 1985.

At the very least, just holding a container of sand from an exotic place and using your imagination can transport you there.

Related links

• http://www.radionz.co.nz/national/programmes/thiswayup/audio/201846925/global-sand-shortage
• http://www.radionz.co.nz/national/programmes/thiswayup/audio/201857801/the-sand-collector
• https://www.radionz.co.nz/national/programmes/sunday/audio/2018654652/global-sand-shortage-vince-beiser-s-warning-over-concrete-use​