What is Danby marble, and where does it come from?
Last updated November 2026.
Quick answer
- Rock type
- Marble; low-grade metamorphosed carbonate (Vermont)
- Quarry
- Underground room-and-pillar quarry, Danby, Vermont
- Formation age
- About 450 million years (Shelburne Formation)
- Absorption (one variety)
- 0.08% by weight
- Density (one variety)
- 2,732 kg/m³ (about 170.6 lb/ft³)
- Varieties
- Imperial to Mariposa, a white with black and gray veins
Danby marble is white marble quarried from an underground room-and-pillar quarry on Dorset Mountain in Danby, Vermont. Varieties run from the clean white Imperial to veined types like Mariposa. It is a calcium carbonate marble, so it is dense but etches in acids and needs sealing in a bathroom.
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What is Danby marble?
Danby marble is the white marble of Danby, Vermont, taken from a large underground quarry in a body of marble known as the Shelburne Formation. Marble is limestone that has been metamorphosed by heat and pressure, and the Vermont carbonate sediments were altered into low-grade marbles by folding during the Taconian mountain-building event. Tight folds thickened the beds, which gave the quarry its deposit.
Danby is a place and a family of varieties, not a single slab. Imperial is the most popular and the cleanest white, and Mariposa is a white with rich veins of black and gray. A sample is the only safe way to judge a particular slab.
What are the properties of Danby marble?
| Property | Danby marble |
|---|---|
| Rock type | Low-grade marble altered from Cambro-Ordovician carbonate sediments by Taconian folding [2] |
| Quarry | Northeast flank of Dorset Mountain in Danby; room-and-pillar workings in operation since 1903 (state geologic survey) or 1906 (local history) [2] |
| Workings | 25 acres (state survey) or 28 acres (local history); haul roads reach about 2,800 feet into the mountain [2] |
| Formation | Shelburne Formation, a 450-million-year-old marble deposit [1] |
| Varieties | Imperial, the most popular, through Mariposa, a white with rich veins of black and gray [1] |
| Water absorption (one variety) | 0.08% by weight; apparent porosity 0.201% [3] |
| Density (one variety) | 2,732 kg/m³ (about 170.6 lb/ft³) [3] |
| Strength (one variety) | Compressive 116.7 MPa (about 16,900 psi); modulus of rupture 16.6 MPa (about 2,400 psi) [3] |
| Abrasion resistance (one variety) | 16.24 mm [3] |
Numbers in brackets refer to the sources at the end of this page. Natural stone varies block to block.
Planning a piece in Danby marble?
Tell us about the room. We reply within one business day with options, and every quote gives the exact dimensions and weight of the piece.
Where does Danby marble come from?
The quarry sits on the northeast flank of Dorset Mountain in Danby. The Vermont Geological Survey describes it as the world's largest underground quarry, and a local historical society uses the same claim. Treat the superlative as a trade description, since neither source documents the comparison. The two also disagree on dates and size: 1903 and 25 acres in one, 1906 and 28 acres in the other.
Workings use a room-and-pillar method. Columns of marble are left standing to support the mountain while saws remove blocks from the rooms between. The historical society reports a tunnel about a mile long that descends some 600 feet, with ceilings 30 feet high and blocks weighing 45 tons. The state survey places the current work area about 2,800 feet into the mountain. The marble from here has been used on the US Supreme Court and the Jefferson Memorial.
How does Danby marble look, and how does it vary?
Mostly white, with variation in how much veining shows. The clean end is Imperial; the veined end is Mariposa, with black and gray lines. Stone World also lists Fantastico Danby, supplied by the company that operates the Danby quarry, though that listing gives only technical figures and no appearance notes.
Marble varies by bed and by block. Buy from a sample cut from the lot you will receive, and view it in the room's own light before approving a vanity top or tub.
Is Danby marble porous?
Dense for a marble. One variety's producer data lists water absorption of 0.08% by weight, apparent porosity of 0.201%, density of 2,732 kg/m³, compressive strength of 116.7 MPa, modulus of rupture of 16.6 MPa and abrasion resistance of 16.24 mm. Stone World states that technical details give a frame of reference only and that testing should be repeated for each project.
Low absorption slows staining, but it does not stop acid etching. Calcite is under Mohs 4 and fizzes in dilute acid, which is the cause of the dull spots marble shows after contact with vinegar, citrus or some cleaners.
| Property | Value | Note |
|---|---|---|
| Water absorption | 0.08% | By weight; one variety |
| Apparent porosity | 0.201% | One variety |
| Density | 2,732 kg/m³ | About 170.6 lb/ft³ |
| Compressive strength | 116.7 MPa | About 16,900 psi |
| Modulus of rupture | 16.6 MPa | About 2,400 psi |
Source: Stone World, Stone of the Month, Fantastico Danby Marble (Oct 19, 2020). Imperial and other varieties may differ.
Can Danby marble be used in a bathroom?
Yes, in the same ways as other white marbles: vanity tops, shower walls, floors, basins and tubs. Honed faces hide etching better than polished ones, and a penetrating sealer slows staining, though it does not protect against acid.
Clean with pH-neutral stone cleaner, wipe up toothpaste, cosmetics and cleaners promptly, and avoid vinegar, citrus and tub cleaners. For a tub, see stone bathtub care; for how weight and floor loading are worked out, see the stone bathtub weight guide. Ask a licensed installer and your local code about floor loading.
How does Danby compare with Carrara and Calacatta?
Danby is an American white marble, so its grey-veined types sit in the same visual family as Carrara and the bolder veins of Calacatta. Quarries differ in crystal size, background tone and vein pattern, so side-by-side samples settle it. The broader marble page covers etching and sealing common to all of them.
Does Pietra Fonte make pieces in Danby marble?
We carve marble, travertine and onyx to order; ask whether this stone is available for your piece. We make no promise on any one variety or quarry, and every quote gives exact dimensions and weight. See the stone library or write to us about a one-off piece through bespoke.
Sources
Every piece is made to order. Tell us about the room and we reply within one business day.
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