Wood’s Chrome Mine is the classic American locality for crystallized brucite. Its best specimens are not merely “old Pennsylvania” curiosities; they are benchmark brucites: pale, lustrous, translucent plates and rounded aggregates that show the mineral in a sculptural, collectable form rather than as anonymous foliated masses. The finest pieces display stacked pseudohexagonal blades, pearly to waxy faces, and a subdued color range from colorless and white through grayish and pale yellow-green to the soft green tones most prized from the locality.
Photo: Wikimedia Commons
The mine sits in the State Line chromite belt of southern Lancaster County, near the Maryland line, in serpentinized ultramafic rock. That setting matters to the brucite. Wood’s was a chromium mine first, but the same magnesium-rich serpentine environment that hosted massive chromite and magnesiochromite also produced a remarkably rich suite of magnesium, chromium, nickel, and carbonate minerals: brucite, magnesite, hydromagnesite, deweylite, serpentine varieties, chromian antigorite, clinochlore, chromium-bearing clinochlore, zaratite-like nickel carbonate material, gaspéite, and related species. The locality’s specimens often carry the visual vocabulary of that environment—gray-green serpentine matrix, black chromite, creamy magnesian minerals, and occasionally the emerald-green accents collectors associate with old “zaratite” labels.
The historic importance of Wood’s Chrome Mine is twofold. Industrially, it was the largest and most famous chromite mine of Pennsylvania and Maryland, and at one time one of the world’s important chromium sources. Mineralogically, it became a foundational American collecting locality: specimens from the 19th-century workings entered old institutional and private collections, and Wood’s brucite remained the standard U.S. crystallized material long after the mine ceased to be an operating chrome producer.
Photo: Wikimedia Commons
Collectors look for brucite that preserves the locality’s unmistakable habit: sharp, broad, pseudohexagonal plates arranged in overlapping blades, rosettes, or hemispherical clusters. Transparency in thin plates, greenish body color, clean pearly luster, and undamaged crystal edges are the key aesthetic markers. Old labels are especially valuable here, because much of the best material was collected during the mine’s 19th-century productive life or from later dump collecting, and because “Texas, Pennsylvania” labels can be vague without a clear Wood’s Chrome Mine attribution.
Search for specimens: View all brucite specimens from Wood’s Chrome Mine, Lancaster County, Pennsylvania, USA
Wood’s Chrome Mine, also known historically as Wood’s Mine, is a former chromium mine near the small locality of Texas in Little Britain Township, Lancaster County, Pennsylvania. The locality lies close to Octoraro Creek and the Pennsylvania–Maryland line, in the State Line Chromite Mining District. Mindat places the mine at approximately 39° 43' 54" N, 76° 6' 24" W; the older geographic term “Texas” is a source of label confusion because it has been used broadly for several nearby chromite and serpentine localities.
The deposit is a chromite deposit hosted by serpentine. Later analytical work on the chrome ore showed that analyzed Wood mine ore falls within the magnesiochromite composition field, even though the older mining and collector literature routinely uses “chromite.” The ore body was famously irregular: historical descriptions record an outcrop of massive chromite about 30 feet long and 6 feet wide, narrowing at shallow depth and then expanding below to a much larger ore zone. The ore body plunged southward and was mined down the plunge to approximately 720 feet.
Wood’s was opened in the late 1820s and worked steadily for much of the 19th century, with a major interruption from 1868 to 1873 when the mine flooded. Earlier accounts describe production on the order of hundreds of tons per month before the Civil War; by the late 1860s, output had fallen sharply as foreign and western chrome ores entered the market. Operations ceased in the early 1880s, after the mine had served for a time as a reserve source against the uncertainties of shipping western chromite to eastern users.
The mine was revisited during later chrome-revival efforts. In World War I, National Minerals Co. of Wilmington, Delaware, reportedly reopened and retimbered an old shaft locally called the Dog Pit to a depth of 125 feet, but the prospects were disappointing. In 1937 the American Chrome Corporation unwatered the mine for examination by W. D. Johnston Jr. of the U.S. Geological Survey and Edward Sampson of Princeton University. The old workings were then dangerous and deteriorated, with caving ground, rotten timbers, and mud and water obscuring the deeper levels.
For collectors, the important production was not just the chrome ore but the dump and wall-rock mineral suite. The USGS described Wood’s as a famous mineral-collecting locality and recorded abundant brucite, deweylite, magnesite, hydromagnesite, zaratite, and genthite, with additional associated minerals including olivine, clinochlore, antigorite, chromian antigorite, serpentine, penninite, calcite, dolomite, and magnetite. Later locality databases add species and refinements including gaspéite, dozyite, maucherite, millerite, pyroaurite, vesuvianite, and others.
Collecting access has changed decisively. The property is not an open collecting locality, and current locality references note that the mine has been closed to collectors since summer 2012. Historic dumps and underground workings should be regarded as private and hazardous unless explicit permission is obtained from the landowner and all safety requirements are met.
Wood’s Chrome Mine brucite is Mg(OH)2, and its signature form is platy: tabular crystals with pseudohexagonal edges, often stacked, overlapping, or grouped into rounded rosettes and hemispherical aggregates. The plates may be sharply outlined and broad for the species, with individual crystals on documented specimens reaching centimeters across. Mindat records the locality as having produced a brucite crystal to about 0.2 m, a size that helps explain why Wood’s has such a towering reputation among brucite localities.
The color is usually restrained rather than flamboyant. Typical specimens are white, colorless, gray-white, pale yellowish, or pale green. The most desirable pieces show translucent plates with a soft green cast and a pearly to waxy luster. In thin areas, the crystals can be transparent enough to pass light beautifully; in thicker stacked plates, they become cloudy, smoky gray, or creamy. The material also has a reported bright blue-white fluorescence, though fluorescence is a secondary feature for most cabinet collectors compared with crystal form and condition.
Matrix varies. Some specimens are essentially brucite-dominant plates or rosettes, while others sit on dark serpentine or chromite-rich matrix. Associated minerals documented from the locality and relevant to brucite specimens include clinochlore, chromium-bearing clinochlore, hydromagnesite, magnesite, deweylite, serpentine-group minerals, chromite/magnesiochromite, dolomite, calcite, and nickel-bearing green carbonate material historically labeled zaratite. Collectors should be especially attentive to old green labels and green coatings: some Wood’s “zaratite” material has been analytically questioned and may be gaspéite or a more complex nickel hydroxycarbonate mixture rather than true zaratite in the strict species sense.
Size ranges from thumbnails and miniatures with rosette clusters to substantial cabinet plates. Documented public images include a 4.2 x 2.9 x 2.8 cm rosette miniature, 9.4 x 6.6 x 3.0 cm and 11.3 x 6.8 x 3.6 cm cabinet specimens with sharp plates, a 14.5 x 11.4 x 3.0 cm large cabinet specimen with translucent crystals to 2 cm, and a large 19.5 x 14.5 x 3.2 cm plate. The finest examples are judged by crystal sharpness, transparency, plate size, greenish color, undamaged edges, sculptural arrangement, and historical provenance.
The first authenticity question is locality, not treatment. Wood’s brucite has a distinctive habit, but “Texas, Pennsylvania” and “Lancaster County serpentine” labels can be imprecise. Serious buyers should prefer specimens with old labels, institutional or dealer provenance, or a documented chain of ownership. Labels from “Wood’s Chrome Mine,” “Wood’s Mine,” “Texas, Little Britain Township,” or “State Line District” may all be legitimate, but broad labels should be weighed carefully against the specimen’s appearance and associated matrix.
The second issue is condition. Brucite is soft, cleavable, and easily bruised. Wood’s pieces commonly show edge wear on the broad plates, broken blade tips, abrasions on pearly surfaces, small pressure cracks, and partial detachment from matrix. Large old plates may have internal veining or cleavage lines that are natural to the mineral but still affect display quality. Repairs and stabilization should always be disclosed, especially on rosettes and large stacked plates where individual blades can separate.
No widely documented, locality-specific fake or treatment problem is associated with Wood’s Chrome Mine brucite in the major locality references. The practical risks are mislabeling, over-optimistic condition grading, and confusion with other pale platy minerals or with brucite from other classic localities. Because Wood’s material is old, collectible, and historically important, a modest specimen with an excellent label can be more desirable than a visually similar but undocumented piece.
Market availability is limited and episodic. Specimens appear through old collections, specialist dealers, auctions, and estate dispersals rather than as newly mined material. Fine cabinet pieces with broad translucent plates and strong provenance can be expensive; a large old Wood’s brucite offered through a dealer aggregation site in late 2025 was listed at $9,500, reflecting both the locality’s status and the scarcity of major specimens. Small or worn examples are more accessible, but sharp greenish crystals with undamaged plates are genuinely scarce.
Wood’s Chrome Mine reads like a 19th-century American mineral locality compressed into one hillside: a world ore source, a difficult underground mine, and a specimen locality whose best pieces outlived the industry that exposed them.
The old mining accounts make clear how irregular the ore body was. At the surface the massive chromite outcrop was described as 30 feet long and 6 feet wide. At 20 feet depth it narrowed, then opened again into a body 120 feet long and 10 to 35 feet wide. Deeper still, the ore zone reached its greatest recorded length of about 300 feet, and mining followed it down the plunge to roughly 720 feet. A quoted 1867 report described the mine as 700 feet deep and stated that the vein was “very irregular,” at one place 20 feet wide, then reduced to mere strings, then widening again.
Water shaped the mine’s history almost as much as ore. From 1868 to 1873, Wood’s was idle because of flooding, apparently when pumping capacity could not keep pace. After operations resumed, it never returned to its earlier dominance. The chrome trade had changed: Turkish ores were entering the U.S. market at low prices, California ores were coming in, and the eastern chromite belt was sliding from world supplier to local relic. Before the Civil War, Wood’s was reportedly producing 400 to 500 tons per month; afterward, accounts give only 500 to 600 tons per year.
The mine did not die all at once. Around 1880 to 1882, the Tyson Mining Company kept Wood’s open as a reserve source in case western chromite shipments faltered. During World War I, National Minerals Co. returned to the district, reopened the Dog Pit, unwatered it, and retimbered it down to 125 feet. They found ore stringers, but not enough promise. In 1937, the American Chrome Corporation tried again, unwatering the old mine for inspection. What they found was not a ready source of wartime ore but a dangerous remnant: caving ground, rotten timbers, bulkheaded stopes, and deeper levels hidden under mud and water.
Against that industrial story runs the quieter collector story. The dumps and wall rock carried the minerals that would keep the name alive after chromite mining ended: brucite, deweylite, magnesite, hydromagnesite, green nickel carbonates, chromian serpentines, and black chromite. Old club and museum notes from the 20th century show how firmly Wood’s had entered collector culture. In 1951, L. J. Duersmith, curator of mineralogy at the Franklin and Marshall College Museum in Lancaster, published a Rocks & Minerals article because he had received enough inquiries during 1950 about the famous mine that an updated account was needed. By then, Wood’s was already a historic locality rather than a working industrial mine, but the brucite had become the durable prize.
Even the name “Texas” has its own field-note charm. Samuel G. Gordon wrote that the locality name covered two townships and was a relic of a time when “precise statement of the source of a mineral was considered an unnecessary refinement.” For collectors today, that sentence is more than a historical aside. It is a warning label. Old “Texas, Pa.” specimens may be treasures, but the serious collector still has to ask: Texas where, and from which mine?
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