Crystals by Color

Green is one of the most common colors in the mineral world, and it shows up in an enormous range of stones — from the banded, deep green of malachite to the soft mint of amazonite and the lively yellow-green of peridot. Because so many unrelated minerals can be green, the color alone tells you surprisingly little about what a stone actually is. A green pebble in your hand could be a copper carbonate, a feldspar, a gem-quality olivine, or simply quartz stained by an impurity, and each of those behaves completely differently.

Blue is one of the rarer and more striking colors a stone can take, which is part of why blue crystals have been prized for thousands of years — lapis lazuli was ground into the ultramarine pigment of Renaissance paintings, and turquoise has been treasured from ancient Egypt to the American Southwest. Yet despite their shared color, blue stones are a wildly mixed group: some get their color from copper, some from a sulfur-bearing mineral, some from trace iron and titanium, and some are not really pigmented at all but flash blue because of the way light bounces inside them.

Purple crystals have a regal reputation, and amethyst — the purple variety of quartz — is the stone most people picture first. But "purple" stretches from the palest lilac of lepidolite to the deep violet of amethyst and the swirling royal purple of charoite, and that range is shared by several unrelated minerals. The same violet color can sit on a hard quartz, a cleavable fluorite, a soft lithium mica or a hard sapphire, so the color says far less about the mineral than it first appears.

Pink crystals are some of the most popular stones in any collection, and it is easy to see why: the color reads as soft, warm and approachable, and it spans a huge range of minerals, from the cloudy blush of rose quartz to the candy-striped bands of rhodochrosite. The word "pink" covers everything from a barely-there blush to a deep raspberry rose, and that single color is produced by several completely different minerals with very different hardness, structure and chemistry.

Red crystals run from the soft, glowing orange-red of carnelian to the deep, blood-dark red of garnet and the brick tones of red jasper. It is one of the most eye-catching colors in the mineral world, and it shows up across very different stones — some translucent and gem-like, others solid and earthy. Because so many unrelated minerals can wear a red coat, color alone tells you a stone is red but not what it actually is.

Black crystals range from the glassy sheen of obsidian to the metallic glint of hematite, the brittle columns of black tourmaline, and the smoky depths of dark smoky quartz. Black is one of the most sought-after colors in stone, valued for its grounding, protective associations, yet 'black' covers a surprising variety of very different materials. A black surface tells you the color, not the species.

White crystals and clear, colorless stones belong together, because most people searching for one mean the other too. The group spans the glassy transparency of clear quartz, the milky glow of selenite and milky quartz, the chalky opacity of howlite and magnesite, and the soft floating sheen of moonstone — a surprisingly wide range of looks united by the absence of strong color.

Orange crystals run from soft apricot and peach through warm amber to deep, fiery red-orange, and they include some of the most recognizable stones in any collection — carnelian, citrine, orange calcite and the gem-quality fire opal among them. The shade can be glassy and translucent, banded and waxy, or glittering with tiny flecks, depending on which mineral you are holding.

Yellow is one of the most eye-catching colors a stone can wear, ranging from the soft honey of citrine to the bright brassy glint of pyrite. Because the color reads as warm and sunny, yellow crystals are among the first specimens many collectors notice in a tray of tumbled stones or a museum case. The shade itself can be a clue to what a mineral is, but it is rarely the whole story.

Brown is the color of earth itself, so it is fitting that some of the most grounding-looking stones in any collection wear shades of tan, chocolate, bronze, and amber-brown. Brown crystals range from the smoky translucence of smoky quartz to the banded, woody patterns of petrified wood, and they tend to feel warm, solid, and reassuring in the hand.