CommercialToolry

Explained: Alexandrite Pendant Natural Standards, Composition, and Industrial Use

Types of Natural Alexandrite Pendants

A natural alexandrite pendant is a luxurious and rare jewelry piece that showcases one of the most fascinating gemstones in the world. Known for its remarkable color-changing properties—from green or blue in daylight to red or purple under incandescent light—alexandrite is a prized choice for fine jewelry. These pendants come in a variety of styles, each designed to highlight the stone’s unique beauty while complementing different tastes and occasions.

Natural alexandrite is typically set in high-quality metals such as sterling silver, 14k gold, 18k gold, or platinum, enhancing both durability and elegance. Whether you're drawn to timeless classics, vintage charm, modern minimalism, or opulent designs, there's an alexandrite pendant to match every personality and lifestyle. Below, we explore the most popular types of natural alexandrite pendants, their design characteristics, and ideal wearers.

Classic Solitaire Setting

Emphasizes simplicity and elegance by showcasing the alexandrite as a single, standalone gem.

Advantages
  • Highlights the color-changing effect of alexandrite
  • Clean, timeless design suitable for any occasion
  • Easy to pair with other jewelry
  • Focuses attention entirely on the gemstone’s brilliance
Considerations
  • Limited visual complexity for those who prefer ornate styles
  • May appear understated for formal or dramatic ensembles

Best for: Minimalist lovers, engagement gifts, everyday elegance

Vintage-Inspired Design

Draws from 19th-century and Art Deco aesthetics, featuring intricate metalwork and period details.

Advantages
  • Rich, ornate appearance with filigree, milgrain, or engraving
  • Often includes accent diamonds or colored gemstones
  • Unique heirloom-quality craftsmanship
  • Perfect for collectors of antique-style jewelry
Considerations
  • Higher maintenance due to detailed design
  • Can be more expensive due to craftsmanship
  • Less suitable for casual or sporty outfits

Best for: History enthusiasts, formal events, bridal accessories

Contemporary & Modern Style

Features clean lines, geometric shapes, and innovative settings that reflect current design trends.

Advantages
  • Striking, fashion-forward appearance
  • Uses architectural forms like circles, hexagons, or abstract silhouettes
  • Often crafted in white gold or platinum for a sleek look
  • Ideal for making a bold personal statement
Considerations
  • May go out of style faster than classic designs
  • Less traditional appeal for conservative tastes

Best for: Trendsetters, modern wardrobes, artistic expression

Alexandrite & Diamond Accent Pendant

Combines natural alexandrite with sparkling diamonds to enhance brilliance and luxury.

Advantages
  • Diamonds amplify the sparkle and perceived size of the alexandrite
  • Halo, pavé, or side-stone settings add dimension and glamour
  • Increases overall value and visual impact
  • Excellent for special occasions and gifts
Considerations
  • Higher cost due to additional gemstones
  • Requires more frequent cleaning to maintain shine
  • Diamonds may overshadow the alexandrite if not balanced properly

Best for: Luxury seekers, anniversary gifts, evening wear

Pendant Style Design Focus Best Metal Occasion Longevity
Classic Solitaire Minimalist, stone-centered White Gold, Platinum Daily wear, engagements Timeless
Vintage-Inspired Intricate, ornate detailing Yellow Gold, Rose Gold Weddings, galas Heirloom Quality
Contemporary Geometric, abstract Platinum, Sterling Silver Fashion events, art gatherings Trend-Driven
Alexandrite & Diamond Sparkle, luxury enhancement White Gold, Platinum Anniversaries, milestones Long-Lasting Value

Expert Tip: To preserve the luster and color-changing magic of your natural alexandrite pendant, avoid exposing it to harsh chemicals or prolonged sunlight. Clean gently with a soft cloth and mild soapy water, and store separately to prevent scratches from other jewelry.

Whether you're captivated by the enchanting color shift of natural alexandrite or the artistry of its setting, choosing the right pendant is a personal journey. From the understated grace of a solitaire to the opulent detail of vintage and diamond-accented designs, each style offers a unique way to celebrate this rare gemstone. Consider your lifestyle, fashion preferences, and the significance of the occasion when selecting your perfect alexandrite pendant.

Designs of Alexandrite Pendant Natural: Elegance, Symbolism, and Style

Natural alexandrite is one of the most coveted gemstones in fine jewelry due to its remarkable color-changing properties—shifting from green or bluish-green in daylight to red or purplish-red under incandescent light. When crafted into pendants, the design plays a pivotal role in enhancing this optical phenomenon while reflecting the wearer’s personality and taste. Thoughtful design not only frames the gemstone beautifully but also amplifies its visual impact, making each alexandrite pendant a unique work of art.

Floral and Nature-Inspired Designs

Botanical Elegance

Floral and nature-inspired designs are among the most popular styles for natural alexandrite pendants. These designs draw inspiration from the organic world, incorporating delicate engravings of flowers, vines, leaves, and petals. The alexandrite stone is often placed at the center of the design—symbolizing a blooming flower—to highlight its dynamic color shift.

Artisans frequently use yellow, white, or rose gold to represent stems and petals, creating a lifelike contrast that enhances the gem’s brilliance. These pendants are especially favored by those who appreciate romantic, vintage, or bohemian aesthetics and seek a deeper connection with nature through their jewelry.

Artistic Craftsmanship

Many high-end designers use hand-engraving, milgrain detailing, and micro-pavé accents to bring floral motifs to life. The interplay of texture and light around the alexandrite creates a captivating visual depth, making the pendant appear almost three-dimensional.

Such intricate craftsmanship ensures that each piece is not only a fashion statement but also a collectible heirloom. Nature-themed alexandrite pendants are ideal for everyday wear or special occasions, offering timeless beauty and emotional resonance.

Geometric and Art Deco Designs

Modern Symmetry and Precision

Geometric and Art Deco-style pendants have gained significant popularity in recent years, especially among lovers of vintage glamour and architectural elegance. These designs emphasize symmetry, clean lines, and bold shapes such as triangles, hexagons, rectangles, and sunburst patterns.

The structured framework of these pendants provides a striking contrast to the organic color play of alexandrite, creating a harmonious balance between rigidity and fluidity. The stone is often set in a bezel or prong setting that aligns with the geometric theme, maximizing light exposure to enhance its color-changing effect.

Luxurious Contrasts

Art Deco designs frequently incorporate contrasting elements such as black rhodium plating, onyx inlays, or diamond accents to frame the alexandrite. Two-tone metal combinations—like white gold with yellow gold—add further sophistication and visual interest.

These pendants appeal to individuals who appreciate 1920s–1930s aesthetics, modern minimalism, or statement jewelry with a bold personality. Perfect for formal events or as conversation-starting accessories, geometric alexandrite pendants exude confidence and refined taste.

Heart-Shaped Alexandrite Pendants

Symbol of Love and Emotion

Heart-shaped alexandrite pendants are among the most cherished designs, symbolizing deep affection, romance, and enduring love. The heart cut is meticulously crafted to preserve the gem’s color-changing ability, ensuring that the stone dazzles in any lighting condition.

These pendants are frequently chosen as meaningful gifts for engagements, anniversaries, Valentine’s Day, or milestone birthdays. The emotional weight of the heart shape, combined with the rarity of natural alexandrite, makes these pieces exceptionally sentimental and valuable.

Personalized Touches

Many heart-shaped pendants include personalized engravings on the back—such as names, dates, or short messages—adding a private layer of meaning. Some designs are enhanced with pavé-set diamonds along the heart’s edge or suspended from a delicate chain with matching diamond accents.

Available in various metal types, including platinum, white gold, and rose gold, these pendants can be tailored to suit individual preferences. Whether simple or ornate, heart-shaped alexandrite pendants remain timeless symbols of heartfelt connection.

Religious and Symbolic Motifs

Spiritual Significance

Religious and symbolic motif pendants featuring natural alexandrite offer a profound blend of faith, heritage, and beauty. Common designs include crosses, the Tree of Life, Hamsa hands, infinity symbols, and Celtic knots—each rich in cultural or spiritual meaning.

The alexandrite is often placed at the focal point of the symbol—such as the center of a cross or the heart of the Tree of Life—to represent divine light, transformation, or eternal love. These pendants serve as both devotional objects and wearable art.

Meaningful Heirlooms

Due to their symbolic depth, these pendants are often passed down through generations as family heirlooms. Crafted with precision and reverence, they reflect the wearer’s beliefs and personal journey.

Ideal for religious ceremonies, confirmations, or as protective talismans, symbolic alexandrite pendants resonate with individuals seeking jewelry that transcends mere aesthetics and connects to a higher purpose.

Design Style Best For Key Features
Floral & Nature-Inspired Nature lovers, romantic styles Organic shapes, gold detailing, central stone placement
Geometric & Art Deco Modern fashion, vintage enthusiasts Symmetrical patterns, contrast metals, diamond accents
Heart-Shaped Gifts, anniversaries, romantic occasions Emotional symbolism, engravings, diamond borders
Religious & Symbolic Spiritual expression, heirloom pieces Cultural motifs, meaningful placement, durable craftsmanship

Important: Natural alexandrite is extremely rare and valuable. Always purchase from reputable jewelers who provide certification of authenticity. Avoid synthetic or imitation stones marketed as "alexandrite." Proper care—such as gentle cleaning and safe storage—will preserve the beauty and longevity of your pendant for generations.

How to Choose an Alexandrite Pendant (Natural)

Selecting a natural alexandrite pendant is a sophisticated decision that combines science, artistry, and personal taste. Known as one of the rarest and most sought-after gemstones, alexandrite captivates with its remarkable color-changing properties and intrinsic value. Understanding the key factors in selection ensures you invest in a genuine, high-quality piece that reflects both elegance and authenticity.

Color Change Properties

Alexandrite is famed for its dramatic and rare ability to shift color depending on the light source—a phenomenon known as the "alexandrite effect." In natural daylight, the stone typically appears as a vibrant bluish-green or teal, while under incandescent or indoor lighting, it transforms into a rich reddish-purple or raspberry hue. This unique optical property is due to the presence of chromium ions in the crystal structure, which absorb light differently across the spectrum.

  • The most valuable alexandrites display a sharp, vivid color shift—ideally from green to red—with high contrast and saturation
  • Stones from different geographic origins may exhibit variations: Russian alexandrite tends to have the most dramatic shift, while Brazilian and Sri Lankan stones may show softer transitions
  • Strong, consistent color change under multiple lighting conditions is a hallmark of fine quality
  • Be cautious of synthetic or imitation stones (like color-change sapphires or glass) that mimic the effect but lack the same rarity and value

Pro tip: Always view the pendant in both daylight and warm indoor lighting to assess the true color shift.

Metal Choice

The metal setting of an alexandrite pendant plays a crucial role in enhancing the gemstone’s appearance and complementing personal style. The right metal not only secures the stone but also influences how its colors are perceived and how well it matches existing jewelry collections.

  • White Gold (14k or 18k): Offers a modern, sleek look that enhances the cool green tones of alexandrite in daylight and provides a neutral backdrop for the red shift indoors
  • Platinum: Extremely durable and hypoallergenic, platinum’s bright white luster intensifies the gem’s brilliance and is ideal for heirloom-quality pieces
  • Yellow Gold (14k or 18k): Brings out the warmer undertones in the stone, especially during its red-purple phase, and pairs beautifully with vintage or classic designs
  • Rose Gold: Adds a romantic warmth and can subtly enhance the red hues, though it’s less traditional for alexandrite

Design insight: Consider the wearer’s skin tone and everyday jewelry preferences—white metals suit cooler tones, while yellow gold flatters warmer complexions.

Cut and Clarity of the Stone

The cut and clarity of a natural alexandrite significantly influence its brilliance, color display, and overall value. Because alexandrite is often found in small sizes and with natural inclusions, skilled cutting is essential to maximize its optical effects while preserving carat weight.

  • Cut: Well-proportioned cuts like oval, round, cushion, or emerald enhance light reflection and color visibility. A poorly cut stone may appear dull or fail to show the full color change
  • Clarity: Natural alexandrite often contains inclusions such as needle-like rutile or fingerprint-like feather patterns. While minor inclusions are expected, eye-clean stones (no visible flaws at 10x magnification) are rare and more valuable
  • Symmetry and Polish: High-quality craftsmanship ensures even facets and smooth surfaces, contributing to sparkle and durability
  • Shape Considerations: Oval and cushion cuts are popular for pendants as they balance brilliance and size appearance, while step cuts (emerald, asscher) highlight clarity and elegance

Expert note: Alexandrite is typically cut into smaller sizes (under 1 carat), so even a 0.5-carat well-cut stone can be exceptionally valuable.

Certification and Authenticity

Given the rarity and high value of natural alexandrite, certification from a reputable gemological laboratory is essential to verify authenticity, quality, and origin. Without proper documentation, it’s difficult to distinguish genuine alexandrite from simulants or synthetic versions.

  • Look for certification from trusted labs such as GIA (Gemological Institute of America), AGL (American Gem Lab), or GRS (Gem Research Swisslab)
  • The certificate should detail the stone’s dimensions, weight, color change range, clarity grade, and whether it’s natural or treated
  • Some reports may also indicate geographic origin, which can impact value—Russian and Sri Lankan alexandrites are particularly prized
  • Avoid stones without certification or those accompanied by vague descriptions like “color-change gem” without specific identification

Red flag: If the price seems too good to be true for a large, vivid color-changing stone, it’s likely not natural alexandrite.

Professional Recommendation: When choosing a natural alexandrite pendant, prioritize the quality of the color change over size. A smaller, vividly shifting stone in a well-crafted white gold or platinum setting will outshine a larger, duller gem. Always request a gemological certificate and purchase from reputable jewelers who specialize in colored gemstones. For daily wear, consider a secure setting like a bezel or four-prong design to protect this precious stone.

Factor High-Quality Indicator Lower-Quality Warning Signs Value Impact
Color Change Strong green-to-red shift in daylight and incandescent light Faint or inconsistent color change; only slight tint variation +++ (Significant increase in value)
Clarity Eye-clean or minor inclusions not affecting brilliance Visible cracks, clouds, or dark inclusions ++ (Moderate value boost)
Cut Well-proportioned, symmetrical, excellent polish Poor symmetry, shallow/deep cut, dull appearance ++ (Enhances visual appeal)
Certification Issued by GIA, AGL, or GRS with full disclosure No certificate or from an unknown lab +++ (Critical for authenticity)

Additional Considerations

  • Setting Style: Solitaire pendants highlight the stone’s color change, while halo settings with diamonds can add sparkle and contrast
  • Chain Compatibility: Choose a chain that matches the pendant’s metal and complements its size—rope or box chains work well for elegant presentation
  • Origin & Rarity: Natural alexandrite from historic sources (Ural Mountains, Russia) commands premium prices due to scarcity
  • Insurance: Given its value, insure your alexandrite pendant with a specialized jewelry insurer
  • Care & Maintenance: Clean gently with mild soap and water; avoid ultrasonic cleaners which may damage included stones

Scenarios for Wearing a Natural Alexandrite Pendant

Natural alexandrite pendants are among the most captivating and versatile pieces of fine jewelry available today. Revered for their rare color-changing properties—shifting from green or bluish-green in daylight to red or purplish-red under incandescent light—these gemstones blend scientific wonder with timeless elegance. While traditionally associated with luxury and sophistication, alexandrite pendants can be styled to complement a wide range of outfits and occasions. From casual daytime wear to formal galas, this guide explores the ideal scenarios for showcasing your natural alexandrite pendant with confidence and grace.

Did You Know? Alexandrite is one of the rarest gemstones in the world and is a June birthstone. Its remarkable color change is due to chromium ions in its crystal structure, making it highly sought after by collectors and jewelry enthusiasts alike.

Everyday Wear: Elevating Casual Style with Subtle Elegance

Despite their luxurious reputation, natural alexandrite pendants can be seamlessly integrated into daily wardrobes. A simple pendant on a delicate gold or platinum chain adds a refined touch to casual ensembles such as:

  • Lightweight cotton blouses paired with dark jeans
  • Simple sundresses or summer tunics
  • Neutral-toned knitwear or cardigans
  • Work-from-home or weekend outfits where subtle sophistication is desired

When styled with minimalistic accessories—like stud earrings or a slim bracelet—an alexandrite pendant becomes a quiet statement piece. It enhances your look without overwhelming it, offering just the right amount of sparkle and intrigue. Opt for smaller stones (0.5–1 carat) or understated settings for a more wearable, day-friendly design.

Styling Tip: Pair your pendant with neutral or monochrome outfits to let the gemstone’s color-changing effect stand out. A white or cream top will highlight both the green and red hues under different lighting conditions.

Evening and Formal Events: The Centerpiece of Elegance

The true magic of a natural alexandrite pendant unfolds in low-light environments, making it an exceptional choice for evening and formal occasions. Whether attending a black-tie gala, wedding reception, or charity dinner, an alexandrite pendant serves as a stunning focal point.

Consider these styling ideas:

  • With Evening Gowns: Choose a pendant featuring a larger alexandrite stone (1+ carats) set in white gold or platinum, possibly accented with diamonds, to complement silk, satin, or velvet gowns.
  • For Cocktail Parties: A heart-shaped or pear-cut alexandrite on a medium-length chain pairs beautifully with cocktail dresses and adds a romantic flair.
  • Under Chandeliers and Candlelight: The gem’s red-purple hue becomes especially vivid under warm lighting, creating a mesmerizing effect that draws admiration.

These pendants are not only beautiful but also symbolize balance and transformation—perfect for milestone celebrations like anniversaries or milestone birthdays.

Occasion Recommended Pendant Style Chain Type Best Lighting for Effect
Everyday Wear Small, solitaire setting Delicate cable or box chain Natural daylight
Office / Professional Classic oval or round cut Slim rope or snake chain Office fluorescent
Weddings & Galas Diamond-accented or halo design Sparkling wheat or figaro chain Warm incandescent / candlelight
Gifting (Romantic) Heart-shaped or engraved design Adjustable box chain Mixed lighting

Personal Gifting: A Meaningful and Lasting Present

Natural alexandrite pendants make profoundly thoughtful gifts, symbolizing love, luck, and life transitions. Their rarity and beauty convey deep sentiment, making them ideal for:

  • Anniversaries: Especially 55th (Emerald Anniversary), though increasingly popular for milestone years due to its uniqueness.
  • Valentine’s Day: Heart-shaped alexandrite pendants express enduring love with a touch of magic.
  • Graduations: A gift of transformation and new beginnings—perfect for someone stepping into a new chapter.
  • Religious Ceremonies: Ideal for confirmations, baptisms, or first communions as a cherished heirloom piece.
  • Birthdays: As a June birthstone, it’s a personalized and meaningful gift for those born in this month.

Many choose to pair the pendant with a personalized note or engrave the back of the pendant with a name, date, or special message, turning it into a treasured keepsake.

Gift Tip: Include a small card explaining the science behind alexandrite’s color change. This educational touch enhances the emotional value and makes the gift even more memorable.

Professional Settings: Sophistication with Subtlety

In corporate environments, jewelry should reflect professionalism without distraction. A natural alexandrite pendant strikes the perfect balance—elegant yet understated. It complements business attire such as:

  • Tailored blazers and sheath dresses
  • Crisp button-down shirts with pencil skirts
  • Power suits in navy, gray, or black

A classic solitaire alexandrite pendant on a short chain rests neatly above the collarbone, enhancing your presence during client meetings, presentations, or networking events. Its subtle color shift adds intrigue without appearing flashy, projecting confidence, attention to detail, and refined taste.

For conservative workplaces, avoid overly large stones or dangling designs. Instead, opt for a modest 0.75-carat stone in a bezel or four-prong setting for a polished, modern look.

Care Reminder: Clean your alexandrite pendant regularly with mild soap, warm water, and a soft brush. Avoid harsh chemicals or ultrasonic cleaners unless approved by a jeweler. Store separately to prevent scratches from harder gemstones like diamonds.

Final Thoughts: A Gemstone for Every Chapter

The natural alexandrite pendant is more than just a piece of jewelry—it’s a dynamic accessory that adapts to your lifestyle, mood, and moment. Whether you're dressing down for a casual brunch or preparing for a red-carpet event, its chameleon-like beauty ensures it remains relevant and radiant. Its symbolic meaning, rarity, and visual allure make it a worthy investment for personal wear or gifting.

By understanding how to style and wear your alexandrite pendant across different scenarios, you maximize both its aesthetic impact and emotional significance. Let this extraordinary gemstone accompany you through life’s everyday moments and most memorable milestones.

Frequently Asked Questions About Alexandrite Gemstones

Q1: What causes alexandrite to change color?

Alexandrite's remarkable color-changing ability, known as the "alexandrite effect," is due to its unique chemical composition and crystal structure. The presence of chromium ions—typically associated with emeralds—plays a crucial role in this phenomenon.

These chromium ions absorb light in both the red and green parts of the visible spectrum, allowing the gem to reflect different colors depending on the light source:

  • In daylight or fluorescent lighting: Rich in blue and green wavelengths, alexandrite appears bluish-green or teal.
  • In incandescent or candlelight: Dominated by red and yellow wavelengths, the same stone shifts to a warm reddish-purple or raspberry hue.

This dramatic shift is rare in nature and makes alexandrite one of the most prized color-change gemstones in the world. The intensity and clarity of the color change depend on the quality of the stone and the balance of chromium within its structure.

Q2: How should I clean an alexandrite pendant?

Cleaning an alexandrite pendant requires care to preserve both the gemstone’s brilliance and the integrity of its setting. Fortunately, alexandrite is relatively durable, but certain cleaning methods should be avoided.

Follow these recommended steps for safe cleaning:

  • Use mild solution: Mix lukewarm water with a few drops of gentle dish soap.
  • Soft brush or cloth: Gently wipe the pendant with a soft-bristled toothbrush or lint-free cloth to remove dirt and oils, especially around the setting.
  • Rinse and dry: Rinse thoroughly under clean water and pat dry with a soft cloth—never air dry, as water spots may form.
  • Avoid: Harsh chemicals (like bleach or chlorine), steam cleaners, and ultrasonic machines, which can damage delicate settings or cause microfractures in the stone over time.

For heavily soiled or antique pieces, professional cleaning by a jeweler is recommended to ensure safety and longevity.

Q3: Can alexandrite be worn every day?

Yes, alexandrite is an excellent choice for daily wear due to its high hardness and toughness. On the Mohs scale of mineral hardness, alexandrite ranks between 8.5 and 9, making it resistant to scratches from everyday materials like dust and glass.

However, while it's durable, proper care enhances its longevity:

  • Avoid impact: Although hard, alexandrite can chip if struck sharply against hard surfaces.
  • Protect the setting: Prongs or bezels holding the stone may loosen over time with constant wear—regular inspections help prevent loss.
  • Remove during strenuous activities: Take off your pendant when swimming, cleaning, or exercising to avoid exposure to chemicals and physical stress.

With mindful maintenance, an alexandrite pendant can remain a stunning part of your everyday jewelry collection for years.

Q4: Why is alexandrite considered so rare?

Alexandrite is among the rarest gemstones in the world, often more valuable than diamonds of comparable size. Its scarcity stems from several geological and geographical factors:

  • Specific formation conditions: Alexandrite forms only under very particular conditions where beryllium (from pegmatites) and chromium (from metamorphic rocks) come into contact—rarely occurring together in nature.
  • Limited sources: The original deposits were discovered in Russia’s Ural Mountains in the 1830s. Today, notable sources include Sri Lanka, East Africa (Tanzania, Madagascar), and Brazil—but yields remain low.
  • Low yield in cutting: Due to its pleochroism and sensitivity to orientation during cutting, a large portion of rough material is lost, reducing the number of high-quality finished stones.
  • High demand: Its color-changing property, historical significance, and status as a June birthstone increase demand far beyond supply.

Truly fine alexandrites—especially those with strong, balanced color change—are exceptionally rare and command premium prices in the gem market.

Q5: How can you tell natural alexandrite from synthetic versions?

Distinguishing natural alexandrite from lab-grown or simulated stones is essential for valuation and authenticity. While both share the same basic chemical composition (BeAl₂O₄ with chromium), key differences exist:

Feature Natural Alexandrite Synthetic Alexandrite
Inclusions Typically contains natural inclusions such as feathers, needles, or mineral crystals—evidence of geological formation. Generally inclusion-free or shows curved growth lines and bubbles, indicating lab origin.
Color Change Subtle, complex shift often with secondary hues; varies with lighting angles. May display a more uniform or overly vivid color change due to controlled conditions.
Price & Availability Very expensive; large, high-quality stones are extremely scarce. More affordable and readily available in larger sizes.
Testing Requires gemological analysis (e.g., spectroscopy, microscopy) to confirm natural origin. Can be identified using advanced tools that detect growth patterns and trace elements.

For assurance, always request a certificate from a reputable gem lab (such as GIA, AGL, or GRS) when purchasing alexandrite jewelry. This documentation verifies whether the stone is natural, synthetic, or treated.