Specialty rock
Specialty rock
From armour rock and large rock for erosion control to gabion rock and spalls for civil and construction projects, we supply the specialty rock products your project needs, with bulk next-day delivery across the Hunter Valley.
Can’t find what you’re looking for, or need a quote?
Hunter Blue Metal supplies rock products for civil works, erosion control and drainage — armour rock for bank stabilisation, gabion rock and spalls for retaining structures, and 1m+ oversized rock for major civil and mining projects. We can source, supply, and deliver at a competitive price with bulk next-day delivery.
Our rock products are sourced from our own quarry and trusted local suppliers across the Hunter region. Every product is selected for durability, consistent sizing, and suitability for demanding applications in civil infrastructure, mining operations, construction, and agriculture. If you need a rock product we don’t usually stock, our sourcing team can find it for you through our network of local quarries and suppliers.
Rock products at a glance
Compare our rock products — match your application to the right size and type:
| Rock product | Size | Typical applications |
|---|---|---|
| Gabion rock and spalls | 100–200mm | Gabion baskets, retaining structures, drainage works, riverbank protection |
| Armour rock | 200–600mm | Erosion control, bank stabilisation, scour protection, breakwater works |
| 1m+ rock | 1000mm+ | Major civil works, large-scale erosion protection, mining hardstand |
| Rail ballast | 32/65mm (ARTC-spec) | Mainline rail construction and maintenance trackbed |
Need a specific rock product or unusual size? Our quarry material sourcing service matches civil, mining and rail projects to the right rock product across our partner network. Call 1300 150 777.
What are specialty rock products?
Specialty rock products are quarry materials selected or produced for specific engineering, construction, and land management applications. Unlike standard aggregates that are crushed and graded to fine sizes, specialty rock products are typically larger materials chosen for their size, weight, durability, and performance in demanding environments.
Armour rock (also known as rock armour or rip rap) consists of large, heavy rocks used to protect embankments, shorelines, channels, and slopes from erosion caused by water flow and wave action. Gabion rock is sized to fill gabion baskets and cages, which are used to build retaining walls, erosion control structures, and channel linings. Spalls are angular rock fragments used as packing, filling, and drainage material in civil and construction applications.
The right specialty rock product depends on your application, the engineering requirements of your project, and the environment the material will be exposed to. Using the correct size and type of rock ensures structural integrity, long-term performance, and compliance with project specifications.
Our Road Construction Products
Explore our range of standard stock specialty rock and crushed rock materials.
Large Rock (1m Plus)
Our 1m plus large rock consists of heavy, durable rocks exceeding 1 metre in size. These oversized rocks are selected for their mass and structural integrity, making them ideal for major erosion control, bank stabilisation, and heavy civil engineering applications across the Hunter Valley and NSW.
Applications:
- Erosion control and bank stabilisation on rivers, creeks, and channels
- Breakwater and revetment construction for coastal and waterway protection
- Scour protection around bridge piers, culverts, and drainage outfalls
- Slope stabilisation on embankments and cuttings
- Feature rock for major civil landscaping and site works
Specifications: Individual rocks exceeding 1 metre in diameter. Selected for density, durability, and resistance to weathering. Suitable for high-energy erosion environments where significant rock mass is required.
Armour Rock (200/600mm)
Our 200/600mm armour rock is a versatile, medium-to-large sized rock product commonly used for erosion protection, drainage works, and retaining structures. The 200mm to 600mm size range provides excellent interlocking properties when placed, creating stable, durable protection for embankments, waterways, and slopes.
Applications:
- Rock armour and rip rap for erosion control on embankments and waterways
- Channel lining and scour protection for drainage infrastructure
- Retaining wall construction and slope stabilisation
- Dam and spillway protection
- Access road edging and site boundary definition on mine and construction sites
Specifications: 200mm to 600mm nominal size range. Angular to sub-angular shape for good interlocking. Dense, durable rock suitable for permanent erosion protection and civil construction applications.
Rail Ballast (32/65mm)
Our 32/65mm rail ballast is a premium crushed rock product used as the foundation layer beneath railway tracks. It distributes load from the sleepers to the subgrade, provides drainage, and maintains track alignment. We supply both ARTC-specified and non-specified rail ballast for projects across NSW and the Hunter Valley.
Applications:
- Track bed construction and maintenance for ARTC and private rail networks
- Load distribution beneath sleepers for mainline and siding tracks
- Drainage layer in rail corridor construction
- Shoulder ballast and track formation works
- Non-specified ballast for industrial and mining rail applications
Specifications: 32mm to 65mm nominal size. Crushed from hard, durable rock with angular particle shape for effective interlocking and load transfer. Available to ARTC specifications with quality documentation on request.
For our full range of rail construction materials including capping and formation products, see our rail construction products
Gabion Rock and Spalls (100/200mm)
Our 100/200mm gabion rock and spalls are angular crushed rock products sized for filling gabion baskets, cages, and mattresses. These products are widely used in civil infrastructure for retaining walls, erosion control structures, channel linings, and drainage applications. The consistent sizing ensures efficient filling and a dense, stable finished structure.
Applications:
- Gabion basket and cage filling for retaining walls and earth retention
- Gabion mattress filling for channel linings and erosion protection
- Drainage blankets and rock-filled drainage structures
- Spall packing behind retaining walls and abutments
- General rock filling and void packing in civil construction
Specifications: 100mm to 200mm nominal size range. Angular crushed rock with consistent grading for efficient gabion filling. Dense and durable for long-term performance in civil and drainage structures.
Need help choosing a specialty rock product?
Our team can recommend the right material for your project and source it for you if it’s not on our standard product list. Whether you need advice on the best rock size for erosion control, the correct gabion rock for a retaining structure, or a specific material for a mining or industrial project, we’re here to help.
Specialty Rock Applications
Our specialty rock products support a wide range of projects across the Hunter Valley and NSW.
Civil and infrastructure
Armour rock and gabion products are essential materials for erosion control, bank stabilisation, retaining walls, channel linings, and scour protection in civil infrastructure projects. Our products are used on council works, state government projects, and major infrastructure developments throughout the Hunter region. For a full range of civil construction materials including road base and aggregates, see our road construction products
Mining and industrial
Large rock and armour rock products are widely used across mining and industrial sites for haul road construction, dam and embankment stabilisation, site drainage protection, and rehabilitation works. We understand the demands of mine-site delivery schedules and can coordinate supply to meet your operational requirements. Learn more about our mining supply capabilities
Rail construction
Rail ballast is a critical component in track construction and maintenance, providing the load-bearing and drainage layer beneath sleepers. We supply ARTC-specified and non-specified ballast for mainline, siding, and industrial rail projects. See our dedicated rail construction page for our full range of rail materials.
Agriculture
Large rock and armour rock products are popular for erosion control on rural properties, creek and dam stabilisation, driveway and access track edging, and general property improvements. Our bulk delivery service makes it easy to get large quantities to rural properties across the Hunter Valley. See our agriculture page for more information.
Why Hunter Blue Metal?
Recognised as the Hunter Valley’s oversized rock specialists, Hunter Blue Metal supplies a comprehensive range of quarry products including specialty rock, aggregates, sand and dust, road base materials, and rail construction materials. Based in the Hunter region, we offer competitive pricing, responsive service, and bulk next-day delivery across Newcastle, the Hunter Valley, and surrounding areas. Our team has the expertise to recommend the right material for your project, and if we don’t stock it, we’ll source it for you.
Bulk transport delivery
Whatever specialty rock products you're purchasing from us, we'll get them to your site safely and efficiently the very next day. We service projects of all sizes, from single-truck loads for rural property improvements to multi-delivery schedules for major civil and mining projects.
Related guide
Helpful explainers and buyer guides from our team:
Sustainability
Sustainability is at the heart of our operations. We reduce our carbon footprint through efficient bulk transport and optimised delivery routes. Our commitment to responsible quarrying practices means you can rely on quality materials supplied with minimal environmental impact.
Frequently Asked Questions
Armour rock (also called rock armour or rip rap) is used to protect embankments, shorelines, waterways, and slopes from erosion. Large, heavy rocks are placed along vulnerable areas to absorb the energy of water flow and wave action, preventing soil loss and structural damage. Common applications include creek and river bank stabilisation, dam embankment protection, drainage channel lining, and scour protection around bridges and culverts. The size of armour rock required depends on the energy of the water and the slope of the embankment.
The size of rock needed for erosion control depends on the water velocity, slope gradient, and engineering specifications of your project. For high-energy environments like fast-flowing creeks or wave-exposed embankments, 1m plus large rock provides the mass needed to resist displacement. For moderate erosion protection, our 200/600mm armour rock is widely used. For gabion structures and channel linings, 100/200mm gabion rock is the standard choice. Our team can help you select the right size for your specific application.
Gabion rock is angular crushed rock sized to fill gabion baskets, cages, and mattresses. These wire mesh structures are filled with rock and used to build retaining walls, erosion control structures, channel linings, and drainage systems. The 100/200mm size range is the most common for gabion applications, as it fills efficiently without leaving large voids while still allowing water to drain through the structure. Gabion structures are widely used in civil infrastructure because they are flexible, permeable, and cost-effective compared to solid concrete alternatives.
Yes. Hunter Blue Metal supplies both ARTC-specified and non-specified rail ballast (32/65mm). Our ARTC-compliant ballast meets the strict quality and grading requirements for use on the Australian Rail Track Corporation network. We also supply non-specified ballast for industrial rail, mining rail, and private siding applications. Contact our team for availability, specifications, and quality documentation.
Yes. We offer bulk delivery of all specialty rock products throughout the Hunter Valley, Newcastle, and surrounding regions. Our fleet is equipped to handle heavy and oversized rock loads, and with stock ready to go, we can typically offer next-day delivery. We service everything from single-truck deliveries for rural property works to ongoing supply schedules for major civil, mining, and infrastructure projects.
The right product depends on your application, the engineering specifications of your project, and the environment the rock will be placed in. Our experienced team can recommend the best material for your needs, whether it’s large rock for bank stabilisation, armour rock for erosion protection, gabion rock for a retaining wall, or rail ballast for track construction. Get in touch with your project details and we’ll point you in the right direction.