温度・粘度
Metal Colloid Coloring (Striker Mechanism)
Japanese: 金属コロイド発色
The mechanism by which gold, silver, and copper nanoparticles emit light via surface plasmon resonance. The principle behind Striker glass. The temperature and duration of reheating determine the particle size and color.
Learn More
Metal colloid coloring is a phenomenon in which metals such as gold, copper, and silver, which are dispersed in a glass matrix at the atomic level, nucleate and grow as nanoparticles (colloids) when the glass is reheated (striking) at a specific temperature, resulting in intense colors due to surface plasmon resonance (SPR) (treatise §5.1). Au (gold) exhibits a vivid red (gold ruby) at particle sizes of 10–30 nm, changing to brown or black as the particle size increases. Cu (copper) exhibits a golden-red color, while Ag (silver) exhibits a yellow to amber color. This is the principle behind the coloration of the Bullseye Striker series (Marigold Yellow, Pink, Salmon Pink, etc.).
In practice, “controlling the striking temperature and time” is of the utmost importance; for Gold Ruby, 650°C for 210 minutes (or 700–710°C for 3–4 hours) is considered the standard striking condition. At high temperatures and for long durations, colloidal particles swell and turn brown to black; at low temperatures and for short durations, colloidal formation is insufficient, and the glass remains transparent (colorless). Striker-type glass differs from other coloring mechanisms in that “time, rather than temperature, governs color development.” Furthermore, it is necessary to use it with an understanding of the characteristic that “striker glass changes color significantly between before and after firing” (Chikaoka 2021, p. 143).
Related Concepts
ストライカーガラス（striker-glass）・遷移金属redox（transition-metal-redox）・発色vs変色（coloring-vs-discoloration）・色見本タイル（color-sample-tile）・硫化黒化（sulfide-blackening）
This entry is written in Japanese by Rei Chikaoka and translated for readers outside Japan. If something reads oddly, the original is the source of truth.