Guyana is home to sandstone formed over volcanic rock like granite and basalt.
Collectors may find sandstone, pink granite, tuff, quartzite, and migmatite samples. Precious stones and gems are rare in Guyana.
Guyana is home to tepui, flat top sandstone mountains that have formed when the larger sandstone deposit eroded away over time.
Consider hiring a local guide to explore the rainforest and petroglyphs in southern Guyana.
Some local rock collectors have found basalt, gabbro, limestone and slate.
Types of Rocks In Guyana: A Guide to the 5 Most Common You’ll Spot
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.
Sandstone is created when sand becomes cemented together. Sandstone is a sedimentary rock.
The sandstone that is found in Guyana is 90% quartz. The stone is called quartz arenite and it has a smoother texture than many types of sandstone.
It is often dark gray because of the quartz content, it is a tightly compacted stone and individual sand grains will not be visible on this dense stone.
Tepui, which means “House of the Gods” is a tabletop formation that juts out of the jungle. They are also called islands in the sky and they are made of sandstone (quartzite arenite).
The sandstone is the result of a large sandstone deposit that once covered the granite around the border between Venezuela and Guyana. The sandstone has eroded over time leaving just the Tepui.
Mount Roraima is one Tepui where the border of Guyana, Venezuela and Brazil meet.
Granite is a coarse grained volcanic rock that forms when lava is pushed close to but not through the surface of the Earth. The rock solidifies slowly underground.
Granite can vary widely in color and because of the coarse texture it generally contains more than one color.
In Guyana there are some beautiful pink granites.
Guyana is part of the Guyana Shield and much of that geological formation is granite.
Both northern and southern Guyana have large granite deposits and the stone is used domestically for decorative and architectural purposes.
You may be able to find a wide variety of granite colors as you travel in Guyana.
Tuff is another volcanic rock, but this is formed during a volcanic eruption. When ash flows out of the hot volcanic eruption and solidifies together it is called tuff.
Tuff is a relatively soft stone and often light in color from white, to light red or tan.
The stone has been used in construction since ancient Rome and it often shows holes and pitting because of the varying density of the stone.
Tuff also often contains other stones that are incorporated into the ash flow during a volcanic eruption.
The Guyana Shield has a large ash tuff deposit in part of the Cuchivero Group.
Quartzite is another volcanic rock that is formed when sandstone is heated by magma and solidifies into a very dense stone.
Quartzite is usually formed in the heat and pressure of tectonic movement. This makes it an incredibly hard and dense stone.
Quartzite has been used for stone tools since prehistoric times.
As the name suggests quartzite is formed from sandstone with a high percentage of quartz.
Quartzite can be a sign to some miners that there may be a gold deposit in the area.
Quartzite is often marketed as an alternative to granite for countertops and decorative purposes.
Stones with distinct layering of colors or textures can be classified as migmatite. These rocks are formed by the partial melting of the stone.
These composite stones are often metamorphic and sedimentary rocks that have formed together.
Most often they are granite and not-yet-granite rocks that have not melted.
Migmatite is a beautiful rock formation and it can be identified easily by the light and dark colored layers.
Migmatite can have a variety of compositions but it is defined by the light and dark contrasting layers formed by the partial melting of the stone.
Guyana is home to one of several greenstone belts. These areas are characterized by their green color, but they can have many compositions.
The greenbelt in Guyana is a volcanic rock, mostly granite and basalt with a green hue that results from the presence of gold or copper.
The greenstone belt is a result of magma being pushed to the surface or close to the surface and solidifying into basalt and granite.
Mining operations often look for greenstone belts as an indication of precious metals and ore.
There are some incredible petroglyphs or rock drawings in Guyana. Large granite boulders in southern Guyana are carved in a unique style and can be visited by tourists.
These petroglyphs were first documented in the 1970s by a local anthropologist. There are over 600 petroglyphs that were carved in the stone of Makatau Mountains. in Aishalton, in southern Guyana.
The petroglyphs have been studied by archeologists in the area and they have uncovered stone tools believed to have been used to create the incredible carvings you see there today.
The petroglyphs give incredible insight into prehistoric life in Guyana and continues to be an area of interest to archaeologists today.
There are many tours of the petroglyphs available to tourists in Guyana so be sure to book a trip to the area.
Rock Collecting in Guyana
Guyana is a great place to visit if you like to see more natural geology and unspoiled landscapes. The tourism in Guyana is much lower than surrounding Brazil and Venezuela.
Guyana does have a mining industry and their main mineral exports are gold and aluminum.
Guyana contains some of the most beautiful rainforests in the world and conservation efforts are comprehensive.
The government has established 4 protected areas which make up about 9% of the total area of the country.
The conservation efforts center on preserving biodiversity in the unique ecosystems of Guyana.
One of the most unique areas in Guyana are the flat top mountains or tepui found in the south. These areas contain several endemic species of animals and flowers that are still being studied.