Vermont is a good state for rockhounding. The state – famous for its marble – has a variety of rocks, minerals, crystals, and fossils. The State even experienced a historic gold rush in the 1850s. Vermont is unusual in that it has designated three official state rocks.
State Rocks, Gemstones, Minerals, Fossils, & Dinosaurs
Rockhounding Tip: Knowing state rocks, gemstones, minerals, fossils, and dinosaurs often can be very useful information for rockhounders. Ordinarily, states with significant mineral deposits, valuable gemstones, fossils, or unusual or significant rock occurrences will designate an official state mineral, rock/stone, gemstone, fossil, or dinosaur to promote interest in the state’s natural resources, history, tourism, etc. Accordingly, such state symbols often are a valuable clue as to potential worthwhile rockhounding opportunities.
State Rock: Granite (1992)
Vermont designated granite as one of its three official state rocks in 1992. Granite is an igneous rock, produced by intense heat. Granite is formed from liquid magma deep beneath the earth. Extreme pressures and a slow cooling process bake granite into one of the hardest and densest rocks on the planet. Granite occurs as small to large plutons in the eastern part of the Vermont. It is mainly composed of feldspar, quartz and mica. Most Vermont granite is Devonian in age, making it quite a bit younger than the slates and marble of western Vermont. The granite from Barre is world famous for its use as monument stone.
State Rock: Marble (1992)
Vermont designated marble as one of its three official state rocks in 1992. Marble is a metamorphic rock. It is composed principally of the mineral calcite. The marble in Vermont was formed by the metamorphism of Cambrian to Ordovician age limestones about 300 million years ago. In Vermont, marble occurs in the southwestern part of the state. The marble quarry in Danby is the world's largest underground quarry, covering twenty acres. Vermont marble ranges in color from pure white to black. Vermont marble was used in building the Jefferson Memorial and the Vermont State Capitol. Most marble currently quarried in the state is crushed and used as filler in paint, paper and plastic.
State Rock: Slate (1992)
Vermont designated slate as one of its three official state rocks in 1992. Slate is a metamorphic rock formed by the compaction and heating of clay, silt, or mud. Slate is a very fine-grained rock composed mainly of quartz and mica. Vermont slates formed about 475 million years ago during the Taconic Orogeny, a period of mountain building. When sedimentary rocks, such as shales or siltstones are metamorphosed, they become slate. Vermont slates generally are black, green, purple, or mottled, depending on the amounts of chlorite (green) and iron (red to purple) they contain. Slate is found in southwestern Vermont. Because slate splits into thin slabs, it is used for roofing shingles, sidewalks and floor tiles.
State Gemstone: Grossular Garnet (1992)
Vermont designated grossular garnet as its official state gemstone in 1991. Grossular garnet, technically, is a mineral - a silicate, that is colored brown due to the presence of iron. Some consider grossular garnet from the Belvidere Mine at Eden Mills to be the finest specimen of its kind anywhere.
Vermont designated talc as its official state mineral in 1991. Vermont talc is metamorphic in origin, formed in thin slivers of ocean crust left after the continents collided. Generally found in southwestern Vermont, it is green in color and very soft. Vermont is a significant producer of talc. Ground talc is used in plastics, paper, rubber, and paint as well as in talcum powder. Talc is mined in the Ludlow area.
State Fossil: Delphinapterus leucas (1993)
Vermont designated the “white whale fossilized skeleton at the University of Vermont's Perkins Geology Museum as its official state fossil in 1993. This fossil, Delphinapterus leucas, is a Beluga whale. The fossil, locally know as the Charlotte whale was uncovered during construction of the first railroad between Rutland and Burlington in 1849 in western Vermont. The specimen dates from approximately 12,500 years ago when the Atlantic Ocean flooded the Champlain Basin, which was depressed below sea level by huge glacial ice sheets, inundating it with marine waters. For 2,500 years following that, this region existed as an arm of the Atlantic Ocean known as the Champlain Sea. This particular whale contains the most complete post-cranial remains of the Champlain specimens yet found. It is a toothed whale recognized by its brilliant white to grey-white color, prominent forehead knob or "melon", and lack of a dorsal fin.
State-specific rockhounding books (including the books listed here as well as other books), regional rockhounding site guides, and other helpful rockhounding resources are identified - by category - in the Books & Gear section of Gator Girl Rocks with a link to the Gator Girl Rocks Amazon Store where you may easily browse selected resources and securely place an order. Your order will benefit Charity Rocks!
Vermont Geological Survey
The Vermont Geological Survey is an excellent resource for rockhounders.
- Bradford B. Van Diver, Roadside Geology of Vermont & New Hampshire (1987).
- Allan W. Eckert, Earth Treasures Vol. 1 - Northeastern Quadrant (1985; reprint in 2000).
- James Martin Monaco & Jeannette Hathway Monaco, Fee Mining & Mineral Adventures in the Eastern U.S. (2d ed. 2010).
- Kathy J. Rygle & Stephen F. Pedersen, Northeast Treasure Hunter's Gem & Mineral Guide (4th ed. 2008).
Museums of Interest to Rockhounders
Perkins Geology Museum
University of Vermont – Burlington, Vermont
The museum’s exhibits include local rocks, minerals, and fossils. The museum also exhibits the Vermont State Fossil locally known as the Charlotte Whale.
Fairbanks Museum & Planetarium
St. Johnsbury, Vermont
The museum’s balcony display cases include a variety of rocks, minerals and fossils from the museum’s Vermont Geological collection.
Montshire Museum of Science
The Montshire Museum of Science has a small collection of minerals.
Places to Visit - Interesting Sites To See
Rock of Ages Granite Quarry
Southeast of Barre, Vermont
The Rock of Ages granite quarry is an enormous an open-pit, deep-hole granite quarry nearly 600 feet deep and 50 acres in surface area. Devonian Barre Granite is mined at the quarry. The quarry includes a visitors center as well as a tour of the enormous marble quarry.
Vermont’s state fossil was found near Charlotte in 1849 when railroad workers were constructing the first railroad between Rutland and Burlington.
Rockhounding Sites for Children & Families
Perkins Geology Museum
University of Vermont – Burlington, Vermont
The Geology Department maintains a pile of waste rocks behind Delehanty Hall. Visitors are welcome to collect samples from this pile.
Lessor’s Quarry – University of Vermont Geology Department
Access permission must be obtained from the University of Vermont. The limestone quarry site includes 450 million-year-old Ordovician Period fossils.
North Central Vermont
The term concretion is a general term used for peculiar mineral segregations found in sedimentary deposits. In Vermont, concretions (also known as claystones) are found in the fine-grained silt and the very fine-grained sand layers associated with glacial lake sediments. These very fine-grained layers are commonly called varved clays. Concretions are composed of concentrations of common sediment and cementing materials such as calcium carbonate (CaCO3) and/or iron oxide (FeO2). The cementing material fills in the pore space around the fine sediment grains and binds the sediment to form a variety of shapes. Often, the cement crystallizes around a central nucleus and forms concentrically banded, oval-shaped nodules. Concretions are most often restricted to one narrow bed or layer and thus tend to be quite flat. Button Bay, on the east shore of Lake Champlain, was originally named "Button Mould Bay" for the numerous concretions that were found washed out of glacial lake clay beds now exposed along the Lake Champlain shoreline. The concretions reminded the early inhabitants of the molds used in the making of pewter buttons. The concretions are Pleistocene age (15,000 to 10,000 years old) glacial lake sediments and occur in several locations in north central Vermont including, East Montpelier, Putney, Sharon, and Waterbury.