Rubidium is much like cesium in that it's a solid at room temperature, but liquid just a bit higher. Cesium actually melts in your hand, while rubidium needs to be just a bit warmer. Cesium also has a much prettier color, exactly the color of gold.
They would both, however, explode on contact with moist air, so we keep them both safely locked up.
Click the source link for an interesting story about where this sample came from.
Source: Tryggvi Emilsson and Timothy Brumleve
Contributor: Tryggvi Emilsson and Timothy Brumleve
Acquired: 6 September, 2002