A Guide and Stories in Matter

Stones

Aquamarine

A member of the beryl family, aquamarine ranges in tone from icy blue to seafoam green. Its color comes from iron traces within the crystal structure, and it ranks 7.5 to 8 on the Mohs hardness scale, making it both beautiful and durable. Once used by sailors as a talisman for safe travels, aquamarine is now prized for its clear, refreshing hue that evokes calm and clarity.

Moss Aquamarine

This variation of aquamarine is characterized by its deep, moody tones and natural mineral inclusions that resemble moss or underwater vegetation. These inclusions—typically iron oxides—create a unique, organic pattern in each stone. Structurally the same as aquamarine, it offers a richer, more textured look for those drawn to the unexpected beauty in nature.

Moonstone

Feldspar-based moonstone features a captivating optical effect called adularescence—a soft, glowing sheen caused by light scattering through layered crystal structures. Usually found in soft whites, peaches, or grays, moonstone is softer (6–6.5 Mohs) and best worn in protected settings. It remains a popular choice for its elegant shimmer and dreamy finish.

Kyanite

Known for its sapphire-like blue, kyanite is an aluminum silicate mineral with an unusual trait—it displays two different hardness levels depending on the direction of the crystal axis (4.5–5 and 6.5–7). While not ideal for rings due to its directional softness, it makes striking earrings or pendants and is admired for its natural striations and silky luster.

Tourmaline

One of the most diverse gemstones, tourmaline occurs in nearly every color due to its complex boron silicate structure and variable mineral content. It can even carry electrical charge when heated or rubbed—a property known as piezoelectricity. Its wide palette and good hardness (7 to 7.5 on the Mohs scale) make it a favorite for colorful, everyday wear.

Labradorite

Labradorite is a type of feldspar known for its labradorescence—a vivid play of color in blue, green, and gold tones caused by light reflecting off internal layers. It typically ranks around 6 to 6.5 on the Mohs scale. Discovered in Labrador, Canada, it’s a favorite for those drawn to bold, iridescent stones with a bit of visual drama.

Ethiopian Opal

Formed in volcanic rock, Ethiopian opals are known for their translucent body and vivid flashes of red, green, and blue. Their high water content—often up to 10%—makes them more porous and sensitive to moisture than other opals. This hydrophane quality gives them a captivating, shifting glow but also means they require gentle care. Unpredictable in pattern and wildly expressive in color, each stone feels like a captured burst of light—fleeting, fluid, and alive.

Australian Opal

Australian opals form in ancient sedimentary rock, the result of millions of years of silica-rich water settling and solidifying underground. These opals—especially those from Coober Pedy and Lightning Ridge—exhibit a vivid and stable play-of-color, prized for its consistency and intensity. With a lower water content, they’re less porous and generally more durable, making them a long-standing standard of quality. Where Ethiopian opals feel untamed and spontaneous, Australian opals carry a quiet, enduring brilliance shaped by deep, slow time.

Imperial Topez

This rare variety of topaz boasts warm, golden-orange tones and excellent clarity. The color is due to trace amounts of chromium or iron within the crystal. With a hardness of 8, it’s well-suited for jewelry that’s meant to last. Once reserved for the Russian aristocracy, imperial topaz is still considered a luxurious and refined choice.

Sunstone

Sunstone is a feldspar mineral that contains tiny platelets of hematite or copper, giving it a warm, reflective shimmer called aventurescence. Found in tones of peach, amber, and red, it is relatively soft (6–6.5 Mohs) but visually radiant. Oregon sunstone, in particular, is prized for its natural copper content and golden glow.

Montana Agate

Sourced primarily from the Yellowstone River region, Montana agate is a translucent chalcedony with striking dendritic inclusions in brown, black, or red. These natural patterns are formed by iron or manganese oxides. As a type of microcrystalline quartz (7 Mohs), it’s both durable and captivating, with each stone showcasing a landscape-like silhouette.

Sapphire

Best known in deep royal blue, sapphire actually occurs in a rainbow of colors (except red, which is classified as ruby). It’s a variety of corundum, with its color stemming from trace elements like iron and titanium. Ranking 9 on the Mohs scale, sapphire is one of the hardest gemstones available, making it a practical choice for everyday wear, especially in engagement jewelry.

Rustic Daimond

Also known as salt-and-pepper or galaxy diamonds, rustic diamonds feature natural inclusions that create smoky, speckled patterns. While they still rank 10 in hardness, their unique textures and earthy tones offer an alternative to the traditional flawless diamond. They’re often cut in rose or irregular shapes to highlight their natural character.

Freshwater Pearl

Formed in rivers and lakes by freshwater mussels, these pearls consist almost entirely of nacre, giving them a soft luster and often irregular, organic shapes. Unlike saltwater pearls, which typically contain a bead nucleus, freshwater pearls can be harvested in multiples from one mollusk. Their accessible beauty and variety of shapes make them ideal for modern jewelry.

Tahitian Pearl

Cultivated in French Polynesia from the black-lipped oyster, Tahitian pearls are known for their natural dark hues—ranging from charcoal gray to vibrant peacock green. Their color comes from the oyster’s dark nacre, and each pearl’s surface reflects a range of subtle tones. These pearls are saltwater-cultured and typically larger, adding to their striking appeal.

Keshi Pearl

Keshi pearls are all-nacre, free-form pearls formed when the oyster rejects the implanted nucleus. Because they contain no core, their luster is often exceptionally high. The name “keshi” comes from the Japanese word for poppy seed, a nod to their size and spontaneity. Their irregular shape and pure nacre content make them uniquely captivating.

Akoya Pearl

These classic pearls are grown in saltwater Akoya oysters, primarily in Japan. Known for their nearly perfect round shape and brilliant luster, Akoya pearls are typically white or cream with rose or silver overtones. They are bead-nucleated and cultivated over several months, producing consistently elegant, timeless pearls.

Elements

That Shape Our Stones

Gemstones are the crystalline expression of elemental chemistry and geological pressure. Their color, structure, and clarity arise from a small group of elements—each playing a distinct role in the formation of the stones we use. Here are some of the key players from the periodic table:

Oxygen (O)

Found in nearly every gem-forming compound, oxygen combines with elements like silicon, aluminum, and iron to form strong mineral structures. It’s essential to the crystalline integrity of quartz, feldspar, and beryl, among others.

Silicon (Si)

One of the most abundant elements in the Earth’s crust, silicon is the backbone of many gemstones. It bonds with oxygen to form silica (SiO₂), which makes up quartz, opal, and agate, and serves as the structural foundation in feldspar and tourmaline.

Aluminum (Al)

Aluminum contributes to both hardness and clarity. It forms the core of corundum (sapphire) and is present in topaz, kyanite, and tourmaline. Its compounds create durable, often vividly colored stones.

Beryllium (Be)

Rare and lightweight, beryllium is central to the beryl family, which includes aquamarine. When paired with aluminum and silicon, it creates strong hexagonal crystals that often exhibit excellent clarity.

Carbon (C)

Carbon is the sole element in diamonds, forming under immense heat and pressure into the hardest known natural material. Its strong tetrahedral bonding structure gives diamonds their legendary durability and light dispersion.

Water (H₂O)

While not a mineral itself, water is crucial in the formation of opal. Opal is composed of hydrated silica—tiny spheres suspended in water—which refract light to create its signature play-of-color. Water content can range up to 20%, making opal one of the few gemstones affected by humidity. This internal moisture also contributes to opal’s relatively soft and delicate nature, which is why it requires extra care in handling, storage, and setting.

 

Chromium (Cr)

A trace element with a powerful impact—just small amounts of chromium can dramatically influence color. It gives emeralds and some sapphires their rich green and pink tones.

Iron (Fe)

Iron plays a major role in the coloration of tourmaline, amethyst, and aquamarine. Depending on its oxidation state, it can produce blue, green, red, or even yellow hues in a variety of stones.

Manganese (Mn)

This colorant is especially prominent in pink and red tourmalines. It also contributes to the shimmer in sunstone and can affect crystal clarity and hue in other feldspar-based gems.

Lithium (Li)

Often present in pink and green tourmalines, lithium is a lightweight metal that contributes to color variation and thermal conductivity in the crystal structure.

Potassium (K)

Found in feldspar-based stones like moonstone and labradorite, potassium helps stabilize crystal structures and contributes to the layered architecture responsible for optical effects like adularescence.

Calcium (Ca)

In pearls, calcium combines with carbon and oxygen to form calcium carbonate (CaCO₃), which is deposited in layers of nacre. It’s also found in certain feldspars and agates.