A fine & large antique black marble & specimen stone desk obelisk & thermometer, Ashford Derbyshire, circa 1860.
This large 15.5" tall obelisk is made of Derbyshire black marble. The obelisk is elegantly inlaid with a band of semi-precious polished hard-stone surround the mercury thermometer, including Derbyshire Blue John, Polished slate with fossils, Malachite, Carrara marble, polished agates etc. The ivory panel behind the glass thermometer is engraved with the word "Fahrenheit" and is also marked with levels from "Blood Heat" to "Freezing" 
The base of the obelisk is inlaid with colored stone in a floral white bell-flower & green leaf design, the obelisk is raised on a substantial stepped base.
Condition is very good indeed, no damage or restoration, this very elegant obelisk is ready to grace your home or office.

Ashford Black Marble is the name given to a dark limestone, quarried from mines near Ashford-in-the-Water, in Derbyshire, England. Once cut, turned and polished, its shiny black surface is highly decorative. Ashford Black Marble is a very fine-grained sedimentary rock and is not a true marble in the geological sense. It can be cut and inlaid with other decorative stones and minerals, using a technique known as Pietra Dura. The mineral has been used decoratively since prehistoric times; the first recorded customer was the Elizabethan Countess, Bess of Hardwick in 1580.
There was a thriving trade in the manufacture of urns, obelisks and other decorative items from Ashford Black Marble during the late 18th and early 19th century. John Mawe had a museum in Matlock Bath that dealt in black marble and Ann Rayner engraved pictures, next door at another museum, on black marble using a diamond. Many fine examples of engraved and inlaid black marble exist in local collections, including those of Derby Museum, Buxton Museum, and Chatsworth House, the stately home of the Duke of Devonshire.