Identification guide · Sedimentary Rocks
How to Identify Travertine
Travertine shows a banded or layered structure, typically in shades of cream, tan, and buff, with a texture ranging from dense and compact to noticeably porous and pitted with small cavities. It has a dull to slightly waxy luster, a white streak, and a hardness of about 3, soft enough to scratch with a knife, and it effervesces readily when a drop of dilute acid is applied, confirming its calcium carbonate composition. It is often confused with other dense limestones or with marble, but travertine's characteristic layered banding and frequent small voids, usually absent in marble, help set it apart.
Travertine identification checklist
| Color | White, Cream, Tan, Beige, Banded brown | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Vitreous to dull, sometimes pearly | Fresh surfaces shine like glass; a dull surface usually means weathering, so chip or wet a corner. |
| Transparency | Opaque, translucent in thin layers | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 3–4 | A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. |
| Streak | White | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Fracture | Conchoidal to uneven | Broken surfaces show smooth, curved, shell-like scoops. |
| Specific gravity | 2.4–2.7 | Ordinary rock-like heft (specific gravity about 2.55), similar to quartz. |
Extra tests for Travertine
Acid test. Fizzes in vinegar or dilute hydrochloric acid because of its carbonate content.
Glass check. Travertine shares a glassy luster and conchoidal fracture with man-made glass. Glass sits near Mohs 5.5 and often contains round gas bubbles, so a hardness test and a hand lens separate them.
Travertine look-alikes and how to tell them apart
Conglomerate is harder (Mohs 3–7) than Travertine (Mohs 3–4), so Conglomerate will scratch Travertine and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Travertine vs Conglomerate →
Both sit near Mohs 3–4, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Travertine vs Dolomite →
Both sit near Mohs 3–4, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Travertine vs Calcite →
Both sit near Mohs 3–4, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
Travertine identification FAQ
How can you tell if a rock is Travertine?
Check the color (white, cream, tan, and beige), the vitreous to dull, sometimes pearly luster, a Mohs hardness of 3–4 and a white streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Travertine?
Travertine has a Mohs hardness of 3–4. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
What is the difference between Travertine and Conglomerate?
Travertine (Mohs 3–4, vitreous to dull, sometimes pearly luster) and Conglomerate (Mohs 3–7, variable; dull matrix to vitreous clasts luster) look alike, but hardness, streak and heft usually separate them. See the full Travertine vs Conglomerate comparison for a side-by-side table.
Is Travertine worth anything?
Entry-level Travertine specimens sell for around $1, typical collector pieces about $10, and premium examples $75 or more depending on size, quality and locality.
What color is Travertine?
Travertine is most often white, cream, tan, and beige. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
