2019 - $20 - 1 oz. Pure Silver Coin - Steve: Sky Wonders

From nighttime displays to unusual phenomena, the skies over Canada give us plenty of reasons to look up in awe. Our three-coin Sky Wonders series re-creates some of nature's optical illusions by mixing colour and different lighting technologies. Beginning with a blacklight-activated fire rainbow, each of these three coins is a pure silver snapshot of a naturally occurring phenomenon that is colourful, rare… and completely spellbinding.

A rainbow is welcome after any rainstorm. But in Canada, a more unusual sight in the sky is a fire rainbow... which isn't a rainbow at all! The unusual band of colours blazes across the summer sky on this coin, where our version of the optical illusion is amplified by a blacklight-activated effect.

This rare halo takes the form of a wispy, rainbow-coloured cloud or band in the sky.

Unlike a true rainbow, a fire rainbow requires no rain; instead, the fair-weather phenomenon appears when the sun hangs high in the sky and the cirrus clouds align. When light passes through these high-altitude clouds, it is refracted by plate ice crystals within. These crystals act like tiny suspended prisms that produce the curious rainbow pattern seen on this coin.

Specifications
No. 172799
Mintage 5,000
Composition 99.99% pure silver
Finish proof
Weight (g) 31.39
Diameter (mm) 38
Edge serrated
Certificate serialized
Face value 20 dollars
Artist Tony Bianco (reverse), Susanna Blunt (obverse)