I didn't apply any particular Materialize classes for this image gallery. It has been built with the same code as the Foundation Masonry gallery (which didn't have any particular Foundation classes either). This is also my first work with the newly launched SD3.5, which has a nifty little feature for the quick adding or replacing of images.
The images and captions are placed in a container 'inner', which is again inside the container 'masonry-css-item'. If you want to add to or subtract from the number of images, it is the latter container you need to duplicate or delete. The images are initially put into one single column, and then I used the 'Multi-column' feature on the Styles pane to change the number of columns at the different breakpoints. The scaling of the images when hovering over them is also set differently at each breakpoint.
If you want to use this gallery in your own work, please provide your own images. And don't forget to remove my images also from the 'img' folder in the Resources. Otherwise your project file size will be quite massive. Select the container 'masonry-css' to make a component. And finally, grab the wee bit of styling in the Page manager Head section.
Two of the images are from Russia, all the rest of them are from Southern Norway. I've mentioned the name of some towns, Oslo, Arendal, Grimstad and Tvedestrand, and the bit of sea, Skagerak. If you wonder where they are, you can look them up on the map provided. I live near Arendal.