top of page

Starac factory of calcite fillers and granules

We deal with the exploitation and processing of stone aggregates, with the main emphasis on the production of calcite products.

We employ 45 workers, and we are proud of the fact that many workers have been with us for many years. Our management structure is very flat - no hierarchy - so decisions are made quickly and responses to customer needs are immediate and extremely flexible.


According to the analysis of the growth of the global market of calcite fillers, a stable growth in sales of calcite fillers is predicted, including for small companies such as Starac d.o.o. a high growth tendency is not unusual, the field of activity and the scope of business, in addition to growth, guarantee its stability. Fillers are one of the best-selling products, the use of which improves the properties of plastics, paints, plasters, coatings, rubber and adhesives.


With smart investments in the latest industrial and laboratory equipment, expert and intelligent associates and employees, and international marketing, the company Starac d.o.o. she ensured a successful career on the Croatian and foreign markets.

The company currently owns the White Rock factory in Siverić and a crushing plant at the quarries in Planome near Trogir.


Above all, STARAC d.o.o. has always been customer-oriented and we have two clear and important goals:

To provide our customers with the material they need, when they need it, and at the right price.

To continue our business in a way that is completely sympathetic to the environment.


White Rock Granules of high purity calcium carbonate


In our factory in Siverić, we process very high purity limestone for the production of our White Rock granule range of granulated calcium carbonates. The range of White Rock granules is a granular product available in sizes from 100 µm to 3000 µm. Within our dedicated processing facility, we crush, grind, dry and classify pure limestone to produce granules of exceptional purity and consistency. Our extraordinary level of attention to detail ensures that our customers receive only the finest granular limestone from the Planom quarries. We have all the necessary certificates, so you can trust us to deliver quality products all year round.


White Rock Fillers (Powder) of high purity calcium carbonate


The quarries in Planome near the town of Torgir are home to our White Rock fillers range of ground calcium carbonate (GCC). In our facilities, we process high-purity carbonaceous limestone, which results in a fine powder of extremely high quality. Our rigorous processing operations include crushing and grinding the raw stone before drying and checking for impurities. The resulting product is then ground and reclassified, and this is how we get our top White Rock filler range. White Rock filler is known for its excellent purity and consistency and is available in a variety of sizes from 1 µm to 100 µm, making it suitable for a number of applications. All of our White Rock fillers are certified so customers can be sure they are dealing with a company they can trust.

White Rock

Tank packing, paper bags, big-bag


We are committed to providing a quality service that includes the packaging and transportation of our products. White Rock granules and calcium carbonate fillers are available in Bulk (tank), paper bags of 25 kg and Big Bag filling up to 1200 kg. All products in paper bags are on pallets and wrapped in foil. White Rock granules and fillers are supplied in a wide variety of sizes to meet the requirements of every customer.


Calcium carbonate is an extremely versatile mineral present in many everyday items, from adhesives and sealants to animal feed and landscaping. Using limestone from Planog, which is of high purity, we produce quality products suitable for numerous applications.

Loading truck White Rock



STARAC d.o.o. is the largest Croatian producer of calcium carbonate, which is used in the production of feed mixtures.


Calcium carbonate plays an important role in animal nutrition as a dietary supplement. Our wide range of dried powders and granules are used as a natural source of calcium and as an inert carrier for various other vitamins and nutrients. The quality of our limestone is unsurpassed, it contains almost 99.5% calcium carbonate - one of the highest levels available.


High-purity limestone, with a low level of acid-insoluble compounds, is an essential component of feed for poultry, pigs and cattle and helps bone development. Poultry especially needs grits in the stomach to facilitate digestion and strengthen the shells for proper egg production. Adding forage calcium carbonate to their diet can help achieve this, resulting in better, healthier birds and better quality eggs.


Calcium carbonate is also used as a fortifier in pet food and bone strengthening supplements. Our granulated limestone is also used by farmers to dose homemade mixed feed.

We strictly control the granule size of our carbonates ensuring that we meet the strict requirements of the animal feed industry. In our factory in Siverić and at the quarry in Plano, we have specially equipped laboratories with expert staff, so you are guaranteed products of high purity.

White Rock - Starac



Calcium carbonate is a widely used additive in adhesives and sealants for a number of beneficial reasons.


The addition of this natural compound can reduce the cost of production while simultaneously improving processing characteristics and increasing the overall durability of the final product. By strengthening adhesives and sealants, calcium carbonate can help improve the durability of finished works such as bathroom and kitchen tiles.


In Starac d.o.o. we produce ground limestone fillers for use in areas where high loads are essential, such as ceramic tile adhesives, grouts and joint fillers - sometimes making up to 80% of the formulation. Special attention is paid to particle size control, which helps in a smooth, professional finish.





In our factory in Siverić, we produce all types of calcium carbonate suitable for the production of commercial glass and ceramics.


Most commercial glasses are essentially a mixture of silicon, soda ash (Na2O) and lime (CaO). Lime can also be partially replaced by magnesium (MgO) depending on the final application. In order to introduce these minerals into the glass melt, manufacturers will add limestone (CaCO3), which is available in high purity form from our company Starac d.o.o.


Packaging glass, which is used for the production of bottles and jars, is made from a specific mixture of sand, soda, limestone and other additives.


Limestone for glassmaking must be of very high purity and contain <0.035% iron oxide (Fe203). Iron is a serious impurity that can negatively affect the color of the glass. Our White Rock stone and products are made from high purity limestone suitable for the glass industry as they contain extremely low levels of metal contaminants.




Calcium carbonate has traditionally been the source of CaO in raw glazes, and can also be used in low-fire bodies to reduce shrinkage after firing. It is also common to see calcium carbonate included in porous earthenware recipes to prevent the expansion of moisture.

Starac - White Rock



Starac d.o.o. offers a wide range of high-quality limestone aggregates suitable for use in concrete from the limestone quarry in Planome.


Our reputation for supplying high quality concrete aggregates is well known, resulting in a large customer base for sectors such as various concrete mixes, cast stone, masonry, precast, brick, paving and ready mix.


For the prefab sector, we offer a range of powders to suit individual customer needs, together with coarse aggregates for the production of paving slabs, walls and fence posts. Consistency is the key to supplying this market, and in Starac d.o.o. we are focused on providing the highest quality limestone in the industry with a professional level of service.




In STARAC d.o.o. we offer a complete limestone solution for farmers as well as a wide range of limestone products for the agricultural and horticultural industries.


Agricultural limestone is one of the most important agricultural materials used to increase crop yields by limiting the harmful effects of high soil acidity and reducing the use of other, more expensive fertilizers. Considerable research has been done on the optimal pH range for various crops, and the addition of agricultural limestone can help maintain that range.


Unless steps are taken to rebalance the soil by applying calcifying materials, there will be a natural decline in the limestone status of most soils. This results in a natural increase in acidity and in many cases a decrease in soil fertility.




We produce ground calcium carbonate (GCC) powder suitable for the production of numerous plastics and rubber. Major uses associated with polymers include carpet backing, PVC compounds, plastisols, and rubber applications.


Underlay for the carpet


Ground calcium carbonate produced in our factory in Siverić is an important limestone filler for strengthening the latex backing of carpets and rugs. This reinforced backing holds the fibers in place and provides a higher degree of elasticity and stiffness. Adding White Rock filler to the carpet backing also extends the latex emulsion without using expensive materials, reducing overall production costs.


PVC compounds and plastisols


PVC is a very versatile polymer and is used in a wide range of applications from cables, flooring and window profiles to packaging, wall coverings and drainage systems. Limestone fillers such as ground calcium carbonate powders can be added to plasticized PVC and plastisols for improved strength and durability.




Gum can also benefit greatly from added ground calcium carbonate powders. Our limestone fillers are the perfect addition to rubber when used for hoses, tires and extruded profiles to other common rubber components.




Aggregates play a major role in most construction projects and are a key component of concrete and asphalt. The main advantage of using construction aggregates is the possibility of improving the overall strength of the final product. We supply a number of different grades to ensure quality aggregates for the construction industry.


Our construction aggregates are used as subbase and road stone and are often used as fill materials for roadbed formation, drainage and grading, including septic fields and foundations for city offices and parking lots. Our aggregates are perfect for retaining walls and roads, providing much-needed strength to stabilize structures.


Our construction aggregates are also often used as a natural pipe base and fill material to provide a support surface that will not damage the pipe, membrane or other materials placed above.

Our aggregates are in demand for numerous construction and residential projects across the region and we are trusted to deliver high quality products on time, every time. Extracted from the finest selected limestone, our wide range of construction aggregates is known for its durability and quality.



Fine, ground calcium carbonates (GCC) are an important additive for a wide range of surface coatings. We manufacture and supply GCC suitable for base coatings such as decorative paints, textured finishes and plasters but also for more specialized applications such as road marking paints.


Carbonates are also highly desirable for industrial and protective coatings due to their ability to improve product strength and surface finish.


Plasters and screeds have their own special requirements when it comes to ground calcium carbonates. In STARAC d.o.o. we supply numerous grades manufactured from our high purity limestone, suitable for all applications. Furthermore, almost all manufacturers are adopting environmentally friendly technology to reduce the use of solvents.



Bituminous products such as asphalt are often used as cement screeds in the construction and repair of roads, parking lots, pavements and driveways. Since bitumen is naturally black, its use results in a much darker finish compared to cement-based concrete. Similar to cement, asphalt benefits from the addition of our White Rock 32 limestone fillers to help strengthen the final product. We are especially proud that our White Rock 32 filler was installed on the asphalt of the Pelješki Bridge and all its access roads.




In our factory in Siverić, we produce our product White Rock ground calcium carbonate (GCC), which is increasingly used as a substitute for cement in concrete and ready-made concrete products.


Our Planome facility supplies limestone aggregates for concrete applications, however, we have recently seen increasing interest in our White Rock fine aggregates as a replacement for Portland cement in many types of concreting.




The use of ground calcium carbonate as a component in concrete can improve the density of the mixture, the surface finish and the performance of concrete in the plastic and hardened states. The use of limestone as a substitute for cement produces light colored concrete suitable for architectural applications. In addition, GCC can also help achieve environmental performance improvements as it results in significantly lower CO2 emissions compared to Portland cement.


Precast concrete


Ground calcium carbonate is increasingly used in applications such as pre-cast concrete products, including paving blocks, paving slabs and roof tiles, as well as ready-mix concrete and self-compacting concrete (SCC).


Paper industry


Our limestone that we produce in Planome is used as a wet slurry made up of mixtures of stone dust and water in the paper industry. The use of minerals in paper production has long been known, kaolin and clay are the main raw materials used as fillers in paper production, but their price is high, while calcium carbonate is abundant in nature. Our limestone from Planog has a lower production price and gives the final product a much whiter color. In the environment of paper production, which is usually an acidic environment, by using calcium carbonate to change to a neutral medium, it becomes an alkaline environment, which is very good for paper production.


Our calcium carbonate products are used as a filler in the production of writing paper, printing paper or packaging paper or cardboard. The filler in the paper has the following advantages compared to the type without filler: the produced paper has a smooth surface, is brighter, has a higher gloss and improved printability.

Calcium carbonate is also used as a coating agent in paper, which means an increase in the quality of the paper surface. The coating process largely leaves the surface of the paper uniform for better printing.

bottom of page