A co-worker must have brought this sample to me. I don't remember.
I now do the photography with a 100mm macro lens on a full-frame digital camera, with a diffuser to soften and spread the sunlight. The sand is on a white porcelain platter, placed close to the minimum focusing distance so the magnification is close to 1:1 on the sensor. In editing I adjust color balance and contrast moderately, so details show up better. I crop a roughly 4000-pixel-wide section from the original image, and scale that to 1584 X 1056 pixels for the blog. The final step is a modest unsharp mask.
Because I'm more interested in showing the beauty of the sand, the scale in these images varies a little, from about 3cm across to 3.5cm. I show multiple images of the sample because one isn't enough.
Hawai'i, Maui, Wailea Beach
Click on an image to see it full size.