Ruby Color Research Articles

On the Role of Tin in Copper Ruby Glass

Tin has so far been believed to reduce cuprous copper during the striking of copper ruby colour. The new view advanced recently on production of copper ruby colour does not involve tin in the striking mechanism. As tin is essential in large-scale production of copper ruby glass, its role has been investigated and is described in this communication. Copper ruby glasses of soda-lime-silica type, with and without tin were melted. The ‘critical’ melting stage was found to be almost absent in glasses without tin whereas it lasted for a considerable period in glasses containing tin. The glasses melted without tin were grey yellow to yellow brown even on heat-treatment, indicating the presence of metallic copper. It suggests that Cu+ got reduced to Cuo in the melt. This does not happen when copper ruby glass is melted with tin. The findings indicate that instead of Cu+, Sn++ might be getting preferentially reduced when tin is present. It would appear that Sn++ retards the reduction of Cu+ to Cuo in the melt. Thu...

Studies on the colloid-coloured Glasses, (I)

Selenium ruby color can be obtained with ordinary soda-lime glasses by adding directly to the batch synthesized cadmium selenide or the mixture of cadmium selenite and some reducing agents scuh as metallic aluminium or silicon powder. In the latter case, ruby coloration appears only when the stoichiochemical relation is statisfied between the amounts of cadmium selenite and the reducing agent. From the above results it is concluded that the necessary condition to produce a selenium ruby glass is the existence of cadmium selenide and that the sulfide-sulphur and zinc are not considered to be the indispensable ingredients.

SELENIUM‐RUBY AND OTHER GLASSES COLORED BY SELENIUM*

AbstractData are presented on the development and production of ruby and other colors in glass by employing selenium as one of the colorants. The addition of 0.25% of powdered selenium and 0.30% of metallic cadmium with 0.055% of silicon as the reducing agents in a zinc‐free glass produced good ruby color. The addition of both oxidizing and reducing agents showed that conditions most favorable for the retention of selenium had an adverse affect on the retention of cadmium.The results of day‐tank trials embodying the principles found in this work are listed.

SELENIUM RUBY GLASS*

ABSTRACTThis paper presents the results of an experimental study on the production of selenium ruby glass, particularly on the retention of the colorants during the melting and fining operations. Selenium, cadmium, and sulfur are necessary in the final glass to get a ruby color. Reducing conditions are conducive to the retention of a large percentage of the selenium in the glass, but when conditions are highly reducing, cadmium is eliminated almost completely. The writers believe that too little attention has been given in the past to the chemistry of the entire glass batch, and as a result operators and research workers have often failed to get a ruby glass not because the loss of selenium was too high but because they eliminated the cadmium by maintaining too strongly reducing conditions.A balance must be maintained so that the batch and the atmosphere above it are sufficiently reducing to hold enough selenium in the melt but not so strongly reducing as to eliminate the cadmium.Most of the work reported in this paper was done on soda‐lime‐silica glasses similar to those melted in continuous tanks for the production of machine‐made ware. A glass of this composition, containing 0.03% of selenium, 0.06% of cadmium, and 0.03% of sulfur, will produce a ruby color. The writers have found that if the cadmium is added as cadmium sulfide the final glass will have sufficient sulfur for color development. The use of silicon as a reducing agent is suggested.An arrested‐cooling procedure for developing color is described briefly.

Is the Color of the Natural Ruby Due to Iron?

Is the Color of the Natural Ruby Due to Iron?

Ruby color in glass : A. E. Williams. ( Trans. Amer. Ceram. Soc., xvi, 284)

Ruby color in glass : A. E. Williams. ( Trans. Amer. Ceram. Soc., xvi, 284)

XII. Colours in metal glasses and in metallic films

The present paper contains a discussion of some optical properties of a medium containing minute metal spheres. The discussion is divided into two Parts: the first Part dealing with colours in metal glasses, in which the proportion of volume occupied by metal is small; the second Part dealing with metal films, in which this proportion may have any value from zero to unity. In Part I. the observations of Siedentopf and Zsigmondy beyond the limit of microscopic vision (‘Ann. der Phys.,’ January, 1903) are discussed. It is shown that the particles seen in a gold ruby glass are particles of gold which, when their diameters are less than 0.1μ, are accurately spherical. I have endeavoured to show that the presence of many of these minute spheres to a wave-length of light in the glass will account for all the optical properties of “regular” gold ruby glass, and that the irregularities in colour and in polarisation effects sometimes exhibited by gold glass are due to excessive distance between consecutive gold particles or to excessive size of such particles, the latter, however, involving the former. It is also shown that the radiation from radium is capable of producing in gold glass the ruby colour which is generally produced by re-heating. The method adopted enables us to predict from a knowledge of the metal present in metallic form in a glass what colour that glass will be in its “regular” state.