What does a typical, perfectly healthy vaccinium corymbosum (highbush blueberry) leaf look like?
Vaccinium species are ericaceous plants (acid soil loving) so they will not do well in alkaline soils, and/or being watered with hard water. In fact they have a narrow optimum pH range 4.8 - 5.2 (Source http://www.westernfarmpress.com/management/blueberry-iron-chlorosis-has-multiple-causes)

The pH of the soil will effect the plants ability to access the minerals in needs from the soil, and mineral deficiencies will indeed show themselves in the leaves first. 

Here is a photo of a healthy Highbush Blueberry leaves