Vaseline green glass is a light yellow to light green colored glass prepared by adding trace depths of Uranium oxide compounds to the molten glass. It is appreciated for its attractive color and is also used as an color filter among other uses. It also has the unique property to cause the glassware to glow when near or exposed to any ultraviolet or black light.
While the silica glass is still molten hot, a trace amount of Uranium Oxide is added to the molten glass – the color is quite consistent – and the color is nearly independent upon the amount of Uranium Oxide added. The color, however, is highly dependent upon temperature and can vary from a light lemon yellow at lower temperatures to a darker green at higher temperatures. Naturally, molten hot glass is an orange yellow when hot and the true color can not be seen until the glass has gone through a quasi-static cooling process.
Many people collect objects made from Vaseline green glass, amassing large collections. One popular example of Vaseline green style glass is depression green glass. Modern day Vaseline glass is nearly identical to antique or historical Vaseline glassware, so it can be quite difficult to discern true antique Vaseline green from newer glass. Look for markings on the bottom of the glassware that may indicate age – often times Former manufacturers and former makers of this glass marked it with a symbol such as an 'H' inside a diamond (for the Heisey style glass) or a 'C' Inside a triangle (for the Cambridge glass from Cambridge, Ohio). Newer depression green glass may be marked with a 'B' inside a diamond or a 'B' inside a triangle.
Vaseline green style glass and glassware can be quite easy and entertaining to collect – try to select collector pieces of glass with no flaws or minimal flaws. Look for unique items – or larger larger items that can command real value. Rarity is also important. Keep away from glassware that has small cracks or other flaws as these problems can significantly depreciate the value of the glass and prevent the pieces from increasing in value over time. Also look for marks on the glass to help identify the maker or age of the glass. Most of all, have fun collecting the glass and try to display the glass in windows or with a good back lighting with a black light source. Check LookInTheAttic & Co for more information about collecting Vaseline glass – they carry a wide variety of fine tableware.