Need help with mining basics, page-6

In descriptive terms the terminology is that 1,000m of diamond drilling will generate 1,000m of core. That could be from one hole or a number of holes and is while it is just considered "core" it will be in sections. Unless the rock is very competent and homogeneous the core will be naturally broken at various intervals. If it is solid it will be broken by the drillers at ~3m intervals (the core barrel length) and then again at ~1.2m lengths to fit into the core trays.

Once the core is in the trays it will be logged by a geologist before being cut in half so that samples can be sent away for assay. Typically core is assayed in 1m or 2m increments. A change in structure or mineralisation is also a point to stop and put in a break and start a new sample.

Given the cost to acquire the core it is unusual not to assay all of it... after all data is the most valuable commodity when evaluating a geological resource and you can never get enough of it!!!