Oolitic aragonite occurs naturally in seawater through a chemical and biological process

Learn About Oolitic Aragonite

Oolitic aragonite is a unique type of calcium carbonate that can be found underneath the crystal-clear waters of the Bahamian banks. Its appearance is quite similar to sand, but unlike the sands on the beaches of California or Florida. Though it has the same chemical makeup as calcium carbonate, oolitic aragonite looks different when viewed through a microscope, providing it with a couple of irreplaceable advantages.

Calcium carbonates usually have a building block-like appearance under a microscope. On the other hand, oolitic aragonite looks more like a bunch of interlaced needles. This distinct look affords aragonite a range of advantages, including a higher surface area. Due to it being extremely versatile, calcium carbonate is used in a wide range of applications and we interact with it on a daily basis. The chemical compound can be found in many everyday objects, such as your morning orange juice, your antacid, your toothpaste, your morning newspaper, and even in the carpet under your feet. The issue, however, is that the calcium carbonate used in these applications is obtained from mines throughout the USA, which are essentially non-renewable resources. This method of obtaining calcium carbonate is energy intensive, not sustainable, and leaves a very large carbon footprint. However, there is an environmentally responsible alternative: oolitic aragonite. Oolitic aragonite is a renewable resource that, during its formation, naturally pulls carbon dioxide from the atmosphere.

Oolitic aragonite is biogenic, which means it’s produced by living organisms. It naturally forms during from a phenomenon called a whiting event or ‘whitings’. In satellite imagery, whitings can be seen as feathery white clouds in the water. Researchers initially believed that these were caused by schooling fish causing disturbance in the sandy bottom. It was found, however, to be a phenomenon where oolitic aragonite forms in needle like crystals at 2-8 microns in size. These events are the precursor to the formation of oolitic aragonite sand and other forms of aragonite. On a seasonal basis, blooms of the microscopic plant organisms called phytoplankton move over the shallow banks of The Bahamas. The phytoplankton converts the sun’s rays into energy, simultaneously pulling carbon dioxide from the atmosphere. Then, the carbon dioxide binds to the calcium in the water and produces a calcium carbonate known as oolitic aragonite. The wispy white clouds in the water are actually the formation of oolitic aragonite, which happens extensively in The Bahamas and is among the world’s only biogenic and naturally precipitated calcium carbonates. These whiting events mainly occur twice a year, meaning that the oolitic aragonite deposits are constantly replenished. The Bahamas banks have approximately 50 to 100 billion metric tons of oolitic aragonite reserves, with a conservative estimated annual renewal rate of 14 to 120 million metric tons each year. Carbon dating, a scientific method used to roughly determine the age of objects, showed that majority of the material at the top of these deposits is very new, having 62% of the carbon been created in the last couple of years to no more than 20 years. With this discovery, there is no doubt that oolitic aragonite is a legitimate renewable resource.

Now is the best time to focus on alternatives that are environmentally responsible. Oolitic aragonite is biogenic, renewable and sustainable. When harvested in an ethical and sustainable manner, oolitic aragonite is the perfect eco-friendly alternative to other calcium carbonates. There are some key markets where oolitic aragonite can be used as an eco-friendly alternative, from agriculture to aquarium fishkeeping. Both consumers and companies should be made aware of their options in order for them to be able to make a responsible decision.


Whether in ground or coated form, oolitic aragonite is a viable filler material for plastics. This is another golden opportunity to help the environment by reducing the amount of hydrocarbon-based plastics consumed. With its high pH buffer ability, oolitic aragonite may serve as a neutralizing agent in compostable bioplastic products, specifically to acidic polymers and its base form of lactic acid when material degrades. Moreover, its one-of-a-kind crystallin shape will enhance physical properties such as impact, stiffness, and heat distortion temperatures. Studies are also being conducted to determine the effectiveness of aragonite as a nucleating agent when compared to talc, as its distinct shape provides more nucleating sites than the spherical shape of mined calcium carbonate. In plastic applications, using oolitic aragonite may not only help you to lower your compound or plastic costs, but you may also receive many other added benefits like those that we just described, all while helping our environment.


With its natural ability to buffer the pH level of water, oolitic aragonite is a great substrate for cichlid and marine aquariums. Unfortunately, the aquarium market is replete with brands claiming to be the real thing but are really just crushed limestone from land-based mines. There are also some brands that harvest aragonite but do not have the necessary approvals to do so, which means you may be putting illegally harvested substrate in your tank. Before making a purchase, always double check your oolitic aragonite and its source. If necessary, ask for proof from the company selling the aragonite. Purchasing falsely labeled limestone will cause you to miss out on the plethora of benefits that aragonite provides.


Another area where oolitic aragonite is the clear-cut superior eco-friendly alternative is in agriculture. Aragonite is an excellent soil enhancer and chicken feed additive. It contains approximately 40% elemental calcium and beneficial amino acids, providing much-needed calcium to plants and egg-laying hens more efficiently. Moreover, it keeps the nutrients in the soil in place, thus preventing the occurrence of leaching. Oolitic aragonite is also very easy to spread on your crops or add to your garden.

Play Sand

Oolitic aragonite is also an excellent eco-friendly option for play sand. A lot of play sand brands on the market are derived from silica-based sands. If you don’t already know, silica exposure may cause a dangerous respiratory disease called silicosis. The objects that children play with should be safe, but the unfortunate reality is that most standard play sands on the market are unsafe. Oolitic aragonite is dust-free, quartz-free and, most importantly, silica-free. It also has a smooth texture and is round in structure, whereas standard sands are rough and quite unpleasant to touch. Aragonite is great for building sandcastles and doesn’t pose any safety risks when used indoors and outdoors. When buying play sand for your kids, always remember to consider their safety, followed by the texture and quality of the sand. Oolitic aragonite is indeed the perfect alternative to other sands. It can also do wonders for your garden. These are just a few of the many applications in which oolitic aragonite shines as an eco-friendly alternative. The next time you go out shopping for your garden, your aquarium, or your kids, it’s important to ask questions and make sure that what you are buying is genuine oolitic aragonite. In this blog, we will add more information about the other different applications of oolitic aragonite.


Oolitic aragonite occurs naturally in seawater through a chemical and biological process. In the Bahamas, millions of tons of this mineral accumulate in vast shoals, where under certain conditions, it is accessible for commercial harvest. Oolites are ovoid or egg-shaped particles that form in agitated shallow-marine waters in tropical settings that are saturated with calcium bicarbonate. Carbon dioxide is lost to the atmosphere through degassing as a result of agitation, through elevated temperatures from solar radiation, and the activity of photosynthetic organisms. The loss of CO2 allows precipitation of calcium carbonate in the form of microscopic layers of interlocking crystals of aragonite on pre-existing skeletal or pelletoidal nuclei. Oolitic particles formed in this manner are composed of very pure calcium carbonate with unique physical properties.

Once many layers of calcium carbonate form, the oolitic particle becomes dense and falls out of suspension. In exclusive areas where conditions are right, a ridge of sand-like material will form and extend for more than 50 miles. Throughout the Bahamas more than 1 billion metric tons of material accumulate through this process, making aragonite truly sustainable, and one of the few renewable minerals in the marketplace today.

Oolitic Aragonite is generated by processing raw material and segregating a specific profile that contains only oolitic particles that can be chemically determined to be oolitic aragonite.