The purer the metal, the slower time has an affect on it. This has been true in metallurgy since the copper, bronze, and iron ages. Pure iron is much more resistant to rust, and likewise, pure silver is more resistant to oxidization.
That said, the patina on silver is some of the most visually beautiful things to witness. Of course, similar to watching the grass grow, silver doesn’t incur patina in the blink of an eye. But left to its own natural devices, as the tones darken, the patina’s hue goes from light brass to bright gold, then dark copper with blue orientation, maturing to burnt sienna or velvety ebony. For sterling silver, the process may take a few months, but for fine silver (especially ones without any soldering) the process may take years.
In the picture above are Shiana Stackable Rings in fine silver that we left out to age. After two years, the patina is a pinkish-sephia laced with a slightly iridescent blue. If cleaned now with a brass brush, the rings would resemble a steely gunmetal. And if left to age some more, they would darken to a luxurious matte-black finish.