Now that summer has drawn to a close, we’re taking a look back at some beaches that we visited this summer. Noting that the sand looked and felt different from beach to beach, we sampled a bit of sand from each – and later, from beaches on the west coast as well. The east coast samples were collected at various times through the summer. The California samples were collected in August and September on a drive up the coast from Long Beach to Tiburon.
Just as the character and feel of each of these beaches is different, the sand samples also look quite different. But how different are they really? Take a closer look with a special optical microscope that allows us to acquire a series of images in multiple focal planes and combine them into a single image with a very large focal depth.
Each of the Extended Focus images are a composite of between 90 and 125 optical microscope images taken under comparable lighting conditions. Extended Focus mode allows us to keep all features in these 3-dimensional sample in focus through a depth of more than 1 mm. All of the sands were imaged at an original magnification of 35X so that grain sizes and material “mixtures” could be directly compared.