Astrophyllite - Harnessing Its Unique Zodiac Sign Influence The stunning Astrophyllite can be either brown or yellow in color, or it can even be black. This gorgeous stone needs to be cleaned and cared for. This stone needs to be treated because of its brittle persistence. Purchasing Astrophyllite Jewelry with protective settings is advised in order to lessen the likelihood of scuffs, fractures, or flaking. This stone is a sensitive gemstone due to its low hardness.