Gemstone and abrasive Specimens Pyrope is the only garnet that is always a shade of red. Although less common than most other garnets, pyrope is a common gemstone.
Pyrope is the only garnet whose most common source is igneous rather than metamorphic.
Metamorphic pyrope comes from the metamorphism of the igneous rocks previously mentioned or from magnesium rich rocks subjected to high grade metamorphism. Almandine and pyrope form a series in which iron substitutes for the magnesium in pyrope. In fact, pure pyrope is unknown in nature and the various proportions are referred to as pyrope-almandine mixes. Pyrope is difficult to distinguish from almandine but is usually clear and free from flaws, at least more so than almandine. Color is red to reddish purple and sometimes a deep enough red to appear black.