Tortoiseshell Glass Vase by Keith Rowe

• Tortoiseshell - Tortoiseshell is a translucent material that comes from the horny carapace of a certain types of turtles, including the hawksbill turtle. It is often therefore mounted on a colour underground - often red - or inlaid with gold or silver thread, as seen in Boulle furniture.
  
  The texture and colour nuances of the material are extremely important. Heated tortoiseshell can easily be formed into various shapes. Like other natural materials, tortoiseshell becomes more beautiful with use. In a time before plastic, tortoiseshell was widely used for small objects such as combs and powder compacts.
  
  In 1973, the trade of tortoiseshell worldwide was banned under CITES (The Convention on International Trade in Endangered Species). Prior to importing or exporting items containing tortoiseshell a CITES permit must be obtained. Tortoiseshell items cannot be traded on Ebay.
  
  "Faux tortoiseshell", another case of man initiating nature, is made from old-style plastics such as celluloid and cellulos and is coloured with red, yellow and brown spots to imitate the genuine article. It is commonly used in glasses frames, musical instruments and costume jewellery.
• Pontil Mark - A pontil mark, also known as a pontil scar, is a distinctive mark or scar found on the base of certain types of glass. It is a remnant of the glassblowing process and is particularly associated with handcrafted items made prior to the widespread use of automated manufacturing.
  
  The pontil mark is created during the final stages of production. After the glassblower has shaped and formed the glass object, it is removed from the blowing iron. At this point, the glass object is often attached to a solid rod called a pontil rod or punty for further shaping, finishing, or attaching additional components. The attachment point is typically at the base of the object.
  
  Once the glass item is complete, it is detached from the pontil rod, leaving behind a mark or scar on the base. This mark can take various forms, such as a rough or irregular surface, a concave or slightly recessed area, or a small circular scar. The presence of a pontil mark indicates that the item was handcrafted rather than mass-produced.
  
  Collectors and historians often use pontil marks as clues to determine the age, authenticity, and production methods of glass or ceramic pieces. Different types of pontil marks may suggest different techniques used in the production process. For example, an open pontil mark is one where the scar is left as an exposed, roughened area, while a closed pontil mark occurs when the scar is smoothed or covered in some way. It's important to note that not all handcrafted glass items have pontil marks, as some artisans developed alternative methods for finishing their work. In Edwardian times the pontil mark was oftern ground off leaving a concave circle in the centre of the base of the object.
  
  The use of pontil marks diminished with the advent of industrialization and automated manufacturing processes in the 19th and 20th centuries.
  
  

This item has been included into following indexes:

• Rowe, Keith (Australia) - glass makers 13