TRAVERTINE

( Fr- travertin; Ger- Travertin/Kalktuff; Nor- travertin; Rus- )

TRAVERTINE (See also MARBLE... and RHODOCHROSITE entries.)

A. Mexican onyx bookends (height - 23 cm) exhibiting bands with diverse degrees of translucency. R.V. Dietrich collection. (© photo by Dick Dietrich)

B. Mexican onyx beads, egg (greater axis - 5 cm) and a geometric form. F.S. Dietrich collection. (© photo by Dick Dietrich)

DESCRIPTION: Most travertine used as a gemrock or decorative stone is a white, tan or cream colored, fairly dense (though commonly including irregularly shaped open spaces) rock that consists largely of calcite; some of it, however, consists in part or wholly of aragonite. A few properties of these minerals (for comparison), as well as of travertine, follow:
Calcite:
    Colors - see last paragraph under this (DESCRIPTION) subheading.
    H. 3
    S.G. 2.7
    Light transmission - transparent to translucent
    Luster - subvitreous to pearly
    Miscellany - effervesces with dilute HCl.

Aragonite:
    Colors - see last paragraph under this (DESCRIPTION) subheading.
    H. 3½ -4
    S.G. 2.94-2.95
    Light transmission - typically subtranslucent in all but extremely thin pieces
    Luster - subvitreous to pearly
    Miscellany - effervesces with dilute HCl.

Travertine:
    Colors - see last paragraph under this (DESCRIPTION) subheading.
    H. 3-4
    S.G. 2.0-2.95 with the large range reflecting the fact that several travertines include diverse percentages of open space
    Light transmission - typically subtranslucent in all but extremely thin pieces
    Luster - dull to pearly or even subvitreous
    Miscellany - effervesces with dilute HCl.

With regard to travertine used as a gemrock, Merrill (1895, p.548-549) notes, "Few rocks possess so wide a range of colors or shades of the same color. Pure white, opaque, milk or chalk white to almost colorless, gray, brown in hues from light ochre to deep mahogany, buff, amber, ochre yellow, pink, red, and green are all common; the various hues being sometimes constant throughout large masses, sometimes intermixed and blended, sometimes occurring in alternating parallel bands, and sometimes in distinct veins and spasmodic dashes."

OTHER NAMES:

The names applied to these rocks constitutes a nomenclature nightmare. The fact that travertines have been given all sorts of rock names, both accepted and not accepted, many of which are applied appropriately to other rocks (e.g., alabaster) is extremely unfortunate. This is particularly perturbing, when one realizes that many of these names will undoubtedly persist, at least in the marketplace, well into the future, perhaps forever.

In addition, travertine from several individual deposits has been given its own designation, even though virtually identical travertine from another, in many cases nearby, deposit has been previously named. The following list, far from comprehensive, includes only a few of the more widely applied names -- some of which are quite unacceptable (at least to petrologists) -- thus far given to travertines.

Alabaster (also oriental alabaster, q.v.) - a misnomer applied, especially in the past, by Egyptologists, to onyx marble.
Alabaster onyx - a so-to-speak doubly misnomeredl term sometimes applied to onyx marble.
Alabastro oriental (eastern alabaster) - misnomer applied, especially in southern Europe, to travertine as well as to alabaster per se.
Egyptian alabaster - a misnomer given to onyx marble, particularly that from the vicinity of Thebes, Egypt.
Calcareous sinter (or calcareous tufa) - name often applied, especially in the geological literature, to spring-deposited travertine that typically is spongy and commonly encases reeds, etc.
Cave onyx - misnomer sometimes given travertine in the marketplace (cf. onyx marble).
Cobaltiferous onyx - bluish pink cave "onyx" from Peramoea, Spain.
Gibraltar stone - name frequently given to translucent calcareous speleothem masses -- i.e., to onyx marble -- from the celebrated limestone caves in the Rock of Gibraltar. Much of this travertine exhibits brown banding and veinlike features.
Karlsbad spring stone - a banded travertine, usually recorded as aragonite, deposited around hot springs of Karlovy Vary (Karlsbad), Bohemia, Czech Republic (Formerly Czechoslovakia). This travertine, much used for fashioning trinkets and carvings, is typically red, off-white and reddish brown, with the colors of its bands either natural or dyed.
Mexican agate - misnomer given, fortunately only rarely, to Mexican onyx.
Mosaic agate - misnomer sometimes given brecciated Mexican onyx.
Onychite - stalagmitic carbonate with yellow or brown "veins." This material was used by ancients for making vases, etc.
Onyx marble - translucent, predominantly white or off-white, compact calcite and/or aragonite speleothem material, commonly exhibiting nearly opaque yellowish, tan, brown or gray banding. Onyx marble has been given several other names, many of which are regionally based; a few examples are Algerian onyx, Brazilian onyx (a green onyx marble from San Luis Province, Argentina); California onyx; Iztac chalchijuitl (name, sometimes used in Mexico, for off-white or greenish Mexican onyx.); Java onyx; Mexican onyx (Mexican marble, Mexican jade) -- names widely associated with onyx marble from the states of Puebla and Oaxaca, Mexico; Pedrara onyx (name originally given to onyx marble from a deposit in the Tecali district, which is about 20 miles from Pueblo, Mexico but now also applied to similar rocks from some other parts of Mexico); Tecali and Onyx Tellez (names now widely applied to Pedrara onyx); Utah onyx (from the vicinity of Lehi, Wasatch County, Utah); Yaqui onyx (from Elmarmolito, Baja California Norte, Mexico); and Yava onyx (from Yavapai County, Arizona).
Oriental alabaster - another misnomer given to onyx marble; this is very likely the alabaster of the ancient world.
Ruin aragonite - brecciated Mexican onyx (see paragraph three under OTHER NAMES subheading in MARBLE entry)
Satin spar - though not necessarily travertine or even of similar genesis, it seems noteworthy that this designation, which is applied widely to fibrous gypsum, was originally introduced, in the early 1800s, to describe fibrous calcite and/or aragonite (Spencer, 1897). "Satin stone" has also been applied to this material.
Speleothem - catch-all name for cave deposits that include such formations as stalactites, stalagmites and anthodites, most of which consist of calcite and/or aragonite.
Stalagmitic calcite and stalagmitic marble - speleothem calcite, most of which is apparently from stalagmites but some of which is from stalactites and other speleothems.
Tufa - see Calcareous sinter.

USES: Jewelry, especially pendants and brooches; also bookends, carvings (including chess sets), coasters, goblets, and mosaics for such things as trays, paperweights and vases.

OCCURRENCES: Travertine, by definition, refers to calcareous deposits from groundwater. Such deposits comprise speleothems in caves and diverse deposits of calcareous sinter (also called tufa) where spring waters of certain compositions come to the surface and evaporate or undergo certain chemical and/or biochemical processes that lead to the formation of calcite and/or aragonite rocks.

NOTEWORTHY LOCALITIES: Tuvalu, near Rome, Italy; Bon-Haifa, Mascara Department, Algeria; Turkey; San Luis Province, Argentina; several places in Mexico -- e.g., along the railroad line between Vera Cruz and Mexico City; at Makers Station and near Cave Creek, Yavapai County, Arizona; near Musick, San Luis Obispo County, California. See also localities given after some of the terms listed in the OTHER NAMES section.

REMARKS: The name travertine is "from It.[alian] travertino, older 'a kind of stone to build withall' ... L.[atin] tiburtinus" (O.E.D.) -- i.e., stone from Tibur (ancient name for Tivoli), which is in central Italy, about 25 km east northeast of Rome.

The varieties included under the sack term onyx marble, in particular, take on dyes readily.

Although good travertine rough is readily available, some travertine with less than desired characteristics has also been used as gemrock. Two undesireable features of such travertine are holes and lack of attractive patterns. Some poorer quality travertine has been modified before fashioning: Small holes have been filled with powdered travertine plus some cementing material, and larger holes have been filled with inlaid pieces, in some case so professionally they are virtually undetectable. -- Use of "patched" travertine, however, has only too frequently led to post-fashioning problems; this is true because the original material and the fillings frequently react differently when subjected to heat. Lack of desired patterns, has sometimes been remedied by painting desired patterns on the backs of thin translucent slabs, and then covering the painted surface with a fine cement to make it look like it has been sawn and not subsequently honed. -- In some cases, these man-produced patterns are difficult to distinguish from those produced in nature.

Most, if not all, ancient Egyptian alabaster (Albastra) was probably travertine marble. As such, it was used for all sorts of vessels, including amphorae used to hold wine, oil, or even ashes of the dead.

According to Merrill (1895, p.569) "Among the Aztecs the stone was so highly prized for its beauties that it was deemed too sacred to be given to the ordinary uses of common mortality, and was devoted almost solely to the ornamentation of religious edifices or the manufacture of sacrificial vessels. So strict and arbitrary was this limitation on its use that its Indian name, 'Tecali,' is merely a corruption of the Aztec word 'Teocall' (Lord's mansion), a name given by the Indians to their temples."

SIMULANTS: None that I have seen or seen described.

REFERENCES: Grant, 1955; Merrill, 1895.

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