Products
Appearances
The Nambucca pebbles steadily change in overall makeup from the smallest to the largest gradings. The sands and fine pebbles (1.6mm and 3mm) are composed almost entirely of quartz. As the size of the pebbles increase the quantity of other rock types also increases, particularly the percentage of greywacke (dark grey, highly indurated fine sandstone and siltstone). As a result the appearance of the material changes from a dominant single colour of yellow in the finer sizes through an increasingly speckled appearance in the middle ranges to predominantly grey above 50mm.
The pebbles are particularly well rounded with a tendency for the grey particles to become more disc shaped in the largest sizes. The pebbles rate 7 on the Mohs scale of hardness. They are competent and there are very few broken particles. Thousands of years of percolating rain water and moving ground water has dissolved the shell and other solubles.
Range of Sizes
Austone produces pebbles in eight nominal sizes 1.6mm, 3mm, 6mm, 10mm, 14mm, 20mm, 50mm and 50mm+. Each of these sizes pass through screens of the nominated size and are retained on the size below. This means that pebbles slightly larger and smaller than the ‘nominal’ size are included in the same size batch. Special sizes can be produced, subject to minimum quantities.
Key Features
• Natural stone
• Sized/graded
• Naturally rounded
• Attractive colour
• Hard, strong and durable
Appearances
The Nambucca pebbles steadily change in overall makeup from the smallest to the largest gradings. The sands and fine pebbles (1.6mm and 3mm) are composed almost entirely of quartz. As the size of the pebbles increase the quantity of other rock types also increases, particularly the percentage of greywacke (dark grey, highly indurated fine sandstone and siltstone.) As a result the appearance of the material changes from a dominant single colour of yellow in the finer sizes through an increasingly speckled appearance in the middle ranges to predominantly grey above 50mm.
The pebbles are particularly well rounded with a tendency for the grey particles to become more disc shaped in the largest sizes. The pebbles rate 7 on the Mohs scale of hardness. They are competent and there are very few broken particles. Thousands of years of percolating rain water and moving ground water has dissolved the shell and other solubles.
Range of Sizes
Austone produces pebbles in eight nominal sizes 1.6mm, 3mm, 6mm, 10mm, 14mm, 20mm, 50mm and 50mm+. Each of these sizes pass through screens of the nominated size and are retained on the size below. This means that pebbles slightly larger and smaller than the ‘nominal’ size are included in the same size batch. Special sizes can be produced, subject to minimum quantities.
Key Features
• Natural stone
• Sized/graded
• Naturally rounded
• Attractive colour
• Hard, strong and durable
Fine Sand
Mostly quartz, fine sand mostly less than 0.6mm, primarily used in concrete production. Coarse sand mostly above 1.0mm. Available in bulk loads only.
1.6mm
Mostly quartz, used in swimming pool renders and water filtration. Available in 20kg bags, 1.2t bulk bags and bulk loads.
* Also available in customer’s own branded bags, minimum qtys apply.
3mm
Mostly quartz, used in swimming pool renders, water filtration, paving and mineral processing. Available in 20kg bags, 1.2t bulk bags and bulk loads.
6mm
Mostly quartz with some greywacke, used in paving, aquariums, water filtration and mineral processing. Available in 20kg bags, 1.2t bulk bags and bulk loads.
10mm
Mostly quartz with some greywacke, used in exposed aggregate paving and landscape. Available in 20kg bags, 1.2t bulk bags and bulk loads.
* Also available in customer’s own branded bags, minimum qtys apply.
14mm
Mostly quartz with greywacke, used in exposed aggregate paving and landscape. Available in 1.2t bulk bags and bulk loads.
20mm
Quartz with greywacke, used in landscape. Available in bulk loads only.
50mm
Quartz with greywacke, used in landscape. Available in bulk loads only.
50mm+
Quartz with greywacke, used in landscape. Available in bulk loads only.
How our pebbles are processed
The raw material of sand and pebbles is extracted from the ‘fossil’ sand dune and trucked a few kilometres to the washing and screening plants. Trommels – or barrel screens – are used where the lower section of the barrel rotates through separated bins of water. Inside the barrel there are a series of low retarder plates set to obstruct the smooth flow of material. These retarders cause the pebbles to ‘scrub’ on themselves as a cleaning procedure and also allow any undersized particles an additional means of escape into the appropriate bin. The screening equipment was designed and built in house in order to produce the consistent quality of sizing and cleanliness required.
