A lot of advanced western bottle collectors admire and talk about the sparkling, beautiful fire aqua coloration of western manufactured glass, but that wasn't always the case. When the two most successful glassworks were starting out in San Francisco, the raw ingredients that were being used came mostly from various parts of California, with some experimenting being done along the way to come up with good working formulas of ingredients that could be had locally without incurring substantial expense of having to import them. Eventually it was found necessary to import some of the ingredients to get the quality of glass desired.In the earlier years for the commoner glass, the glassworks would use sands from the North Beach area of S.F. as well as the surrounding hills, along with sand from the Oakland side of the bay. This sand was coarse and not free of iron oxides. Along with glass blowers of limited experience and various skill levels bottles were often made with what I call "in manufacturing flaws", these are often referred to as bruises, crazing, flashes, fractures, etc. They are in reality the result of poor manufacturing process and or annealing process.
Another effect that occurs on early western glass is devitrification, this is caused by the glassblower reheating the glass too often to finish it, causing the crystalization of the surface of the glass, both inside and or outside. This condition is sometimes mistook for haziness or staining in the glass. Examples of this are seen on variant 1 & 2 Lacour's, variant 1 Cassin's and variant 1 Dr. Henley's bitters.
Here is an example of a early western blown variant 1 Rosenbaums Bitters bottle, when placed in a window sill with light, it is easily seen with several in making flaws. Most likely these large western examples were blown during the 1866-67 time frame.
