It is difficult to know, because only about 15 g - 30 g of francium can be found throughout the earth's crust at any given time. Francium is highly radioactive and the half-life of its longest-lived isotope is only 22 minutes.
It is impossible to prepare a large enough sample to observe in the laboratory because the extreme heat of decay would immediately vaporize any quantity of the element large enough to see. http://en.wikipedia.org/wiki/Francium
Here's a nice video detailing some of the properties we would expect francium to have (and explaining why throwing francium in water would make for the YouTube video of the century)