The Lone Star Texas Topaz is a name that points to two distinct but related ideas: the recognition of topaz as the state gem of Texas, formally designated in 1969, and the long-running lapidary tradition of cutting topaz from the Mason County deposits in the Texas Hill Country. There is no single named historical stone called the Lone Star Texas Topaz in the manner of the named historical diamonds, but the phrase circulates in trade and tourism literature as a generic designation for fine Texan topaz, and a specific large-cut stone of this name has been described in some published accounts.

Texas state gem designation

The Texas state gem designation was made by the 61st Texas Legislature in 1969, in the course of a broader designation of state symbols. The designation specified topaz as the state gem and identified the natural blue topaz of the Mason County area as the basis for the designation. This was a significant moment for the Texas lapidary community, since it provided official recognition for material that had been worked locally for over a century but had not enjoyed the commercial profile of Brazilian or Mexican topaz.

The Mason County deposit

The Mason County topaz occurs in pegmatite veins associated with the Town Mountain Granite, a Precambrian-age granite intrusion exposed across the Llano Uplift area of central Texas. The topaz is found as colourless crystals, with rare specimens showing a pale natural blue colour that does not require irradiation to enhance. The natural blue is much paler than the deeper blues produced by irradiation treatment of colourless topaz, and the material is collected and cut as a natural blue gem rather than being subjected to colour treatment. The deposit has been worked by both commercial mining operations and by hobbyist collectors at the well-known Seaquist Ranch, which has long permitted public collecting on a fee-basis.

Notable cut stones

Several large topaz crystals from the Mason County deposit have been cut into prominent stones over the past century. The most-cited Texas-cut topaz is the 2,054-carat cushion-cut Lone Star of Texas, sometimes attributed as the largest cut Texas topaz. A smaller stone, often referred to in legislative and tourism literature as the Lone Star Topaz, of approximately 1,296 carats, has also been cited in various sources. The naming and the precise weights vary across sources and the term Lone Star Texas Topaz does not refer with consistency to a single named historical stone.

The Lone Star Cut

The Texas Faceters Guild, working with the state's lapidary community, developed in the late twentieth century a five-pointed star cutting design known as the Lone Star Cut, intended for application to Texas topaz to produce a faceted stone with a star-of-Texas pattern visible in the table when viewed face-up. The design has been published in faceting design journals and remains in occasional use by Texas-based lapidaries who specialise in state-themed cutting work.

Trade significance

For the wider gem trade Texan topaz is a small and specialised category. The natural blue colour is pale and the material is generally outshone in commercial markets by the irradiation-treated London Blue, Swiss Blue and Sky Blue stones from the wider trade. Within the Texan and broader Southwest US lapidary collecting community, however, the material has a recognised cultural and regional significance that supports a steady market for cut stones, jewellery, and rough material from the Seaquist Ranch and other authorised collecting sites. State-themed jewellery incorporating Texas topaz is a recognised category at Texas regional retail and at lapidary shows.

Care

Topaz, while hard at 8 on the Mohs scale, has a perfect basal cleavage that makes the material vulnerable to fracture along the cleavage plane under sharp impact. Setting and bench-handling of Texan topaz requires the same care that is appropriate for any topaz: avoid mechanical shock, avoid the prong-tightening pressure on the cleavage direction, and avoid ultrasonic cleaning of pieces with internal feathers. With reasonable care the material wears acceptably as a natural blue gemstone in jewellery applications.