I have recently gotten into geology, so please forgive the lack of terminology. Today I found a piece of what I believe to be citrine in my caliche driveway in the Austin, Texas area. I read that natural citrine was uncommon, and that they do not have the reddish hues that mine has. I have found various minerals in the driveway before, such as white quartz, chert/flint, and fossils. The specimen is roughly 1" by 1.5" inches, and the colour varies from a very pale champagne yellow to a dark amber, forming on what I believe is limestone. The crystals are the same height throughout, and are lighter on the edges than in the center. Please give me your thoughts for the identification of this specimen.