Types of Rocks Found on Dominica: A Guide to the 6 Most Common You’ll Spot

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Dominica contains some of the most amazing stones in the Caribbean.

In this article, you’ll learn more about the geology of Dominica.

Types of Rocks Found on Dominica: A Guide to the 6 Most Common You’ll Spot

Disclaimer

The information provided in this article by YesDirt.com is for informational purposes and is subject to change. Laws are updated. Accessibility guidelines and restrictions change. Be sure to confirm the land status and collection rules before you travel to an unfamiliar location or collect any material.

Dominica is a great place to find exposed volcanic rock like Breccias, Red Basalt and Sulfur. The island has been well preserved because of its mountainous terrain and rich thick forests. 

Dominica has 26 mountains and 9 active volcanoes, more than any other island in the Lesser Antilles.  

Dominica has the highest concentration of active volcanoes on Earth. There are 16 active volcanoes in the Caribbean with 9 of those volcanoes on the less than 300 square miles that make up the island of Dominica. 

This list contains the known stones on the island but Dominica still has unsurveyed geological formations where other stones may still be waiting to be discovered. 

Basalt

Basalt is a volcanic rock that forms when lava hardens after being pushed to the surface. Basalt is one of the most common types of volcanic rock and it is very common on Dominica. 

On Dominica there are large areas of Red Basalt on Dominica called The Red Rocks. The Red Rocks are found outside Calibishie in between white and black sand beaches. It is a great location to spend the day. 

The red color is the result of the high iron concentration of Basalt. The Basalt began to oxidize in the salt water of the ocean and turn the stone red. 

In some areas of the island the bright red colored basalt is covered by darker colored younger ash containing tuff. 

Andesite

Andesite is another common type of volcanic rock that is common on Dominica. 

Andesite is a very fine grained rock that is difficult to distinguish from Basalt, but as a general rule Andesite is a lighter colored gray than basalt which tends to have a darker coloring. 

Coloring is the easiest way to tell the two stones apart, but it is not a hard and fast rule.

In differentiating Andesite and Basalt you should consider many factors such as location and texture of the stones. 

Andesite in the North East near Calibishie often contains diamond shaped fragments of quartz. 

Limestone

Limestone is a common sight on many Caribbean islands and it is fairly easy to identify by its fine even texture and relative softness. 

Limestone is a stone that contains calcium from the remains of marine life. When shells and skeletons of these creatures settle to the bottom of the ocean and become a solid stone. 

On Dominica limestone is visible on the West Coast in exposed roadside cuts. Areas where the landscape has been altered to expose the layers of rock and you can clearly see the layers of limestone.  

Divers will enjoy Rodney’s Rock, a beautiful limestone formation with a maximum depth of 110ft. 

The remote location of Rodney’s Rock makes it a good location for those looking to enjoy the rocky beaches in peace. The stones in the area are largely limestone.  

Sulfur 

Sulfur is a bright yellow to green crystal that forms often in areas of volcanic activity and Dominica has the most active volcanoes of any location on Earth. 

Sulfur was traditionally known as Brimstone because of its association with volcanic areas. 

Sulfur crystals are likely to be found in areas like hot springs but they may also be embedded into Breccias, Basalt or Andesite. 

Sulfur crystals have been documented in the Valley of Desolation and the Roseau Valley on Dominica.  

Hot springs are plentiful on Dominica and you may find crystals in the area of: 

  • Ti Kwen Glo Cho
  • Bongo Baths
  • Trafalgar Falls
  • Boiling Lake

Boiling Lake is a great place to find sulfur crystals of many colors as the rocks found around the hot spring are described as rainbow colored.   

Breccias 

Breccia is a conglomerate rock that contains large raw square and broken pieces of other rocks cemented together in a fine matrix of fine grained rock.

Breccias are truly beautiful rocks that are formed  

Breccia are often formed at the base of steep hills which are many on Dominica. The large Breccia formations on Dominica can be found in the multiple valleys and gorges that cover mountainous Dominica. 

The fine matrix that cements the angular, unrounded gravel in breccia is often volcanic ash which is plentiful on the island. 

Pillow Lava 

Pillow lava is formed when lava is extruded under water and floats to the surface due to the trapped gasses in the lava. 

Pillow lava formations can be found around Springfield on Dominica which can be reached on the public road at Antrim. 

Pillow lava is a very interesting formation as you can make out individual pillow lava pieces all joined together like a vertical cobblestone road. 

Black Sand

Dominica is one of the few places on Earth where you can enjoy relaxing on black sand beaches. 

The black sand is a result of the volcanic rock that has broken down to form the sand. In Dominica you can find black sand on the beaches of Secret Bay. 

The black sand beaches on Dominica were created when a basalt lava flow reached the water and the basalt almost instantly formed as the hot lava reacted violently with the ocean water. 

Black sand is rare and it is generally prohibited to remove black sand from a beach. The sand can also get hotter than lighter colored sand so be sure to wear shoes while walking on a black sand beach. 

Black sand is generally rich in iron and may even be magnetic.

Rocks on Dominica

Dominica is one of the most well preserved islands with lush natural forests and a thriving bird population. 

The geology of the island makes it a beautiful place to visit and see the natural beauty of the Caribbean. There are volunteer opportunities to help with the restoration after the 2018 hurricane that did damage to the forests of Dominica. 

When collecting rocks, sand and shells on Dominica remember that 20% of the island is part of a protected island. 

The protected areas prohibit the collection and removal of any natural items from the beaches, forests or hiking areas. 

Consider purchasing stone and gem samples in tourist areas to support the local economy of Dominica. 

The terrain on Dominica means that destructive deforestation practices are impractical on Dominica. The forests have retained their unspoiled beauty. 

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Types of Rocks Found on Dominica