Types of Rocks on Grenada: A Guide to the 5 Most Common You’ll Spot

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

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

Types of Rocks on Grenada: A Guide to the 5 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.

Grenada is a collection of volcanic islands in the Lesser Antilles that is geologically very young. The rocks on the island are basalt, andesite, grenadite, olivine and garnet.  

The rocks on the island are largely volcanic with very little limestone. 

Grenadite 

Grenadite is a stone that is unique to Grenada and is a semi-precious stone in the same family as turquoise. 

Grenadite is a dark green stone with a similar hardness and luster as turquoise. The opaque stone is used in jewelry and often shaped into square stones for necklace and earring settings. 

Grenadite has been present on the island for many years, but it began to be celebrated in 2005 when jewlers began to celebrate this unique stone that can only be found on Grenadite. 

There is one major jewelry maker using and celebrating Grenadite and that is Lisa’s. The company is committed to celebrating the history of the native people on the island, employing citizens of the island and honoring the traditions of the Kalinago people. 

Basalt

Basalt is a common dark colored volcanic rock that forms when lava cools. 

Basalt is abundant on Grenada and the breakdown of the basalt results in fertile volcanic soil that makes Grenada so beautifully green. 

Basalt is under the crust in most areas of the Earth, but only reaches the surface in areas of volcanic activity or movement of tectonic plates. 

The Caribbean Islands of the Lesser Antilles is one of the places of abundant basalt that has been extruded. 

The southeast mountains of Grenada have basaltic flows that are some of the oldest evidence of volcanic activity on the island. 

The rocks in this area of the island show signs of age and weathering. 

Basalt on Grenada often contains crystals of quartz or semi precious stones. These crystals may be apparent to the naked eye or may require magnification to be identified. 

Andesite

Andesite is a lighter colored fine grained stone that results from rapidly cooling lava. 

Andesite on Grenada has broken down into smaller pieces and formed fluvial rock formations when the rock mixed with mud and fine sediment and created layered stone formations. 

Andesite is less common than basalt, but the two stones are often found together and are often not differentiated in the field. 

On Grenada you can find andesite in the lava domes on Mt. Lebanon, Fendon’s Camp and Levera Hill. The eruptions that resulted in these deposits happened during the Miocene epoch. 

The most recent explosion center is on Mt. St. Catherine and that eruption resulted in andesite flows and hot springs. 

You can read more about andesite vs basalt in the linked article.  

Limestone

Limestone is not found in many areas of Grenada, but you may find this light colored relatively soft stone in the National Parks in Grenada. 

Limestone is a rock that is formed from calcium containing shells and skeletons of marine life. 

On Grenada limestone deposits are rare because most of the island was formed by volcanic activity rather than tectonic movement. 

Many Caribbean islands have plentiful limestone which does not support vegetation, but Grenada is a rich jungle because the soil has formed from volcanic rock. 

Limestone can be found in low lying areas on the beaches in Grenada. 

Mt. Alexander has some examples of limestone deposits 100m above sea level. 

Olivene

Olivene is a semi-precious gemstone that can be found on Grenada. The stone forms beautiful crystals that are often found embedded in basalt or andesite. 

Olivene is typically green in color, but it can be yellow to colorless. The stone crystallizes at very high temperatures so it is one of the first crystals to form in volcanic rock. 

The stone weathers quickly and is not often found in sedimentary rocks, but is more commonly found in basalt. 

The gemstone of Olivine is called Peridot and it is the birthstone for August. 

Garnet

Garnet is a beautiful semi precious stone that can be found in many colors. The deep red that is most common is still prized and can be found on Grenada. 

Garnet is a popular stone for jewelry and local garnet is set in jewelry available on the island.  

These stones are often found embedded into volcanic rocks and are also mined by jewelry makers. 

While you can find garnet with careful rock breaking you may find the semi-precious stone by searching drainage areas. 

The volcanic rock on Grenada often breaks up into mudslides or smaller gravel around streams and beaches. Look for the bright red gems in these areas. 

Sulfur 

Grenada has some examples of hot springs which are often good places to find crystalized minerals. 

Sulfur crystals are often found on volcanic islands around hot springs. 

Sulfur crystals usually range in color from bright yellow to bright green. These crystals have a distinct smell and crystal formation pattern. 

The crystals may be found on stones surrounding a hot spring or on stalactites in cave areas where hot springs are close by. 

In Grenada hot springs and boiling springs are mostly located around Mt. St. Catherine, which is the area of the most recent volcanic eruption. 

Rock Paintings 

On the western side of the island there is a large collection of rock art. 

Visitors can see Petroglyph Path with many tour agencies, but not much is known about their origins or their meanings. 

These rocks are volcanic in origin and were worked with stone tools and they depict faces and geometric designs.  

Rocks on Grenada

The rocks on Grenada tell the story of the history of the islands. The rocks on the island have been used for tools and jewelry for many generations. 

The renewed interest in the pre-Columbian inhabitants of the island has renewed conservation of the natural resources of the island. 

The conservation efforts focus on the education of the native young people to become advocates for preserving the natural beauty of their homeland. 

There are several National Parks on Grenada and collecting and removing anything from these areas is prohibited. The National Parks include:

Grand Etang National Park 

Levera National Park 

Queen’s Park 

Be sure that you respect the local preservation efforts by not collecting rock, sand or shells in areas where collecting these items is prohibited.

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Types of Rocks on Grenada