Chalcedony - What is it, quality and care

What is chalcedony?

Chalcedony is a form of microcrystalline quartz (closely related to agate and onyx). This means that the stone consists of very small crystals, which gives it a distinctive soft, slightly transparent expression - often with a waxy sheen when polished.

Chalcedony is often used in:

• rings, earrings, pendants and bracelets

• cabochon cut (smooth, rounded surface) that highlights the stone's glow

• designs where you want a subdued, Nordic and elegant look

Chalcedony colors and expressions

When people say "chalcedony", many think of blue chalcedony but the stone comes in several variants and the look can change a lot.

Typical color tones:

• light blue (classic blue chalcedony with a soft sheen)

• blue-gray (more muted and modern)

• milky white (calm and minimalist)

• greenish shades (may occur in certain variants)

• lavender/pink tones (rarer and very soft in expression)

A beautiful chalcedony often has an even color field and an "inner glow" where the light seems to lie below the surface.

How to assess the quality of chalcedony

Chalcedony is typically assessed on color, uniformity, transparency, surface and abrasiveness.

Color and uniformity

• The more smooth and harmonious the color, the more exclusive the stone is often perceived.

• Very blotchy or uneven colors can appear more raw - which can also be a style.

"Glow and transparency

• Chalcedony is rarely crystal clear, but it can have a beautiful semi-transparent glow.

• Stones that appear vibrant and "luminous" in different lights are often the most desirable.

Surface and finish

• A good polish is important because chalcedony is often worn as a cabochon.

• Small scratches can appear on glossy surfaces, so a nice finish makes a big difference to the overall impression.

Grinding and shaping

• Cabochon is the most common cut and suits the soft look of the stone well.

• A well-executed sanding feels smooth and looks symmetrical in the bezel.

Chalcedony vs. other stones (agate, aquamarine and moonstone)

Chalcedony can resemble several popular stones - especially when it is light blue or milky white.

Typical confusions/alternatives:

• agate: often more banded/patterned than chalcedony (but they are closely related)

• aquamarine: typically more clear and "glassy", often with a cooler blue tone

• moonstone: often has a distinct glow/play (adularescence) that chalcedony usually does not have

• opalite/glass: similar in glow, but different in structure and durability

If you want to be safe, buy from a retailer who is clear about the type of stone and any treatments/coloring.

Caring for chalcedony in jewelry

Chalcedony is relatively robust, but it benefits from gentle care - especially because the surface can get small scratches over time if exposed to heavy wear.

For everyday use

• Remove jewelry when: exercising, cleaning, gardening, showering and swimming

• Avoid direct contact with: perfume, hairspray, creams, hand sanitizer and detergents

• Store the jewelry separately so the chalcedony is not scratched by other jewelry

Cleaning and maintenance

• Wipe with a soft cloth after use

• Clean as needed with lukewarm water + mild soap

• Use a soft brush around the socket if there is dirt

• Rinse gently and dry completely

Important to avoid

• Ultrasonic and steam cleaning (can be too harsh for both stone and bezel)

• Harsh chemicals and abrasives (can dull the surface)

• Hard impacts against metal/stone/table tops (may cause small nicks or scratches)

How to style chalcedony

Chalcedony is ideal for a light, Scandinavian look - especially in blue and milky white shades.

Good combinations:

• silver/rhodium-plated: highlights the cool blue/grey tones and looks very clean

• gold/gold plated: adds warmth and contrast to the light stone and feels more "soft luxury"

• mix with pearls: classic, calm and elegant

• mix with clear stones: light and feminine without being too much