Crizzling
Posting Number 3174 Date: 04/16/19 Return to Posting List
To: Alan, From Scott Hansen
ÿ In Monday's Gazette, Rande Bly stated "Steuben did not make crackle." That is incorrect. There are multiple references to crackled glass in the line drawings and there are examples shown in the Shape Gallery, including such well known shapes as 6199 and 6382.
Shape 6199-Crackled
Shape 6382--Crackled
As for the condition of Brian Severn's candlestick, I think Dick Stark correctly identified the condition as crizzling. Despite the relative "youth" of Carder glass, crizzling occurs in stages and Brian's candlestick could simply be in an early stage. Here is a more complete and coherent definition of crizzling taken from David Whitehouse's Glass Dictionary:
ÿ (or: crisseling)The result of chemical instability in glass caused by an imbalance in the ingredients of the batch, particularly an excess of alkali or a deficiency of stabilizer (usually lime). The instability of the glass results in an attack by atmospheric moisture, which produces a network of cracks in the surface that may feel damp or oily. Crizzling can be slowed or perhaps even halted, but it cannot at present be reversed. Crizzled glass is sometimes described as sick or weeping.
and an associated article
THE STAGES OF CRIZZLING
Stage 1: Initial Stage
Presence of alkali on the glass gives the surface a cloudy or hazy appearance. Tiny droplets or fine crystals can form if there is high (above 55%) or low (below 40%) relative humidity. Glass may feel slippery or slimy. Washing will remove alkali from the surface and the glass will look great.
Stage 2: Incipient Crizzling
Similar symptoms to stage one, but the haziness remains after washing. Close examination using low, raking light may reveal very fine cracks which look like tiny silvery lines or shimmering rays.
Stage 3: Full-blown Crizzling
Cracking has progressed, is easily visible with the naked eye, and often takes on a very uniform appearance.
Stage 4: Advanced Crizzling
Cracking is even deeper. Spalling may occur leading to loss of small chips or flakes from the surface.
Stage 5: Fragmentation Stage
The final stage is observed when the crizzling is so deep that the object cannot retain its structural integrity and separates into fragments. This may happen without any outside intervention or by impact or additional strain to the glass such as that experienced with regular handling.
Images:
Click to view image one: 6199.jpeg
Click to view image two: 6382.jpeg
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