Rosalene

Rosalene Vase Rosaline Water Bottle

Rosalene is a heat sensitive glass, with a milk glass base that contains pure gold which gives it a pink blush when reheated. First done by Fenton in 1976 the original formula proved to be too corrosive for the pots and had to be changed to the formula that is being used currently there is a considerable difference in the coloring between the two, with very noticable transitions between the milk glass and blush, with the blush being a much deeper color, almost to the point of being red instead of pink. The original formula Rosalene was only made for a short period of time and examples are quite scarce.  Dave Osburn aquired a small batch when here bought the Gibson Glass Co. in Milton and we where lucky enough to get a few pieces for Glass Mountain.

Vaseline Opalescent Glass

Very rare VASELINE glass in America must be yellow-green in natural light AND glow. Over the years from 1840-1999 canary/vaseline glass will vary in color intensity and hue with changes occurring about every twenty years. There are also changes from manufacturer to manufacturer and even by the same manufacturer, due to lack of quality controlBy the 1920's and 30's, some vaseline glass was being made, but the color was going out of vogue. Fostoria and Cambridge made some beautiful vaseline glass during the depression years that is true vaseline, but it looks different than what was made during 1885-1895. Fenton's 'Topaz' made during the early 1940's, again took on a different shade as did Fostoria's HEIRLOOM pattern from 1959.     Today's vaseline glass is a very harsh yellow-green (when compared to the glass made in 1885), but it still uses 1-2% of uranium salts to color it.

Vaseline glass has been at least called the following names during the past 160 years: CANARY, ANNAGLEB, VASELINE, CANARIA (by Pairpoint), TOPAZ (by Fenton and others), YELLOW (Fostoria Heirloom pattern), JASMINE (Duncan & Miller) and probably others.

The preferred term for this interesting glass by the majority of collectors is vaseline. One can call it whatever they want, of course, but if they want others to know what they are talking about, they tend to use the word "vaseline" to be understood.

 Coloured glass is produced by using various metal oxides. The colours vary according to the nature and quality of the oxides, the glass mixture into which it is added, and whether or not there is a reducing or oxidizing agent present. A reducing agent removes oxygen from a chemical while an oxidizing agent adds oxygen. Cobalt oxide gives a beautiful dark blue colour, manganese a purple or black colour and manganese used in conjunction with iron and arsenic will produce many shades of amber. Ferrous oxide produces olive green or pale blue. Ferric oxide will produce a yellow colour but requires the presence of an oxidizing agent. Copper gives a peacock blue colour, which can turn green if the proportion of copper oxide is increased. Gold is used for the production of red or ruby glass.

The chemist worked behind the scenes & suddenly stumbles upon the formula to produce heat sensitive glass. The addition of arsenic, uranium or gold to the batch mixture gave the molten glass the ability to change from one colour to another when reheated at the glory hole. The glassmaker controlled the precise area of the colour change by re-heating only the desired part of the glass.

 At the same time, it was discovered that by adding bone ash to the glass, upon re-heating, the piece would turn a pearly white colour; thus the introduction of OPALESCENT GLASS. One record alone provides us with an insight into what was occurring in coloured, heat sensitive glass development. Thomas Webb & Sons Co. in England introduced 65 separate colours between 1875 and 1898, ten of the colours having reference to opalescence. Then came the first developments of Burmese glass. In America in 1883, Joseph Locke registered a patent for Amberina glass & three years later Peach Blow, a cream coloured glass with a heat sensitive overlay, had been developed. From its inception, opalescent glass has enjoyed a widely receptive audience. A young growing market was ready for any touch of brilliance and beauty to display throughout the home. The craze & frenzy to own & display a particular colour & pattern of glass perhaps was not unlike todayÕs ÒBeanie
 Baby" Phenomenon.

There are three kinds of glass known as opalescent. One is blue-tinged, semi-opaque or clear glass with milky opalescence in the center. The colour is produced by the slow cooling of the molten glass in those parts that are thick causing some crystallization inside the glass. This contemporary opalescent glass was first produced in the 1920s and 30s by companies in France such as Lalique, Sabino and Jobling.

The second kind of opalescent glass is hand-blown and is normally made from two layers of glass, the outer layer containing the heat-sensitive chemical.

 The third kind of opalescent glass has a milky white edge or a white raised pattern decorating a coloured pressed glass item. The effect is produced by re-heating parts of the molted glass just as it has started to cool. The heat sensitive chemicals in the glass turn the re-heated sections white. This article will focus on pressed opalescent glass.

Now, about the chemist and chemistry of opalescent glass; In the laboratory, the chemist may have successfully found the perfect combination of ingredients to create a desire effect. Then it was up to the glass craftsman to accurately balance the batch mixture, the heat, the cooling and the physical limitations of molten glass. Added to this, in the early days, the chemistry of coloured glass was not totally understood. Occasionally unusual colours do turn up which are probably experimental pieces or the results of a batch going wrong.

Coloured glass is produced by using various metal oxides. The colours vary according to the nature and quality of the oxides, the glass mixture into which it is added, and whether or not there is a reducing or oxidizing agent present. A reducing agent removes oxygen from a chemical while an oxidizing agent adds oxygen. Cobalt oxide gives a beautiful dark blue colour, manganese a purple or black colour and manganese used in conjunction with iron and arsenic will produce many shades of amber. Ferrous oxide produces olive green or pale blue. Ferric oxide will produce a yellow colour but requires the presence of an oxidizing agent. Copper gives a peacock blue colour, which can turn green if the proportion of copper oxide is increased. Gold is used for the production of red or ruby glass.