There are a lot of Citrine from Minas Gerais which are mostly smoky yellowish brown to orange. This specimen has a brownish yellow core, but the outer layers with the skeletal quartz patterns are more of smoky that is concentrated along some edges. transitions from smoky to citrine are common, since the colour centers of both varieties are closely related. Crystal like his are found in pegmatite pockets around the cities of Aracuai and Itinga, Jequitinhonha Valley.
Picture show are with and without back light for your convenience to understand the colour varies.