Name: Ciel d'Airain
Brand: Pierre Guillaume
Rating: 7.0 (81 reviews)

Guerlain is a prestigious perfume brand with a rich history, known for creating high-quality beauty products. Founded by chemist Pierre-Francois-Pascal Guerlain in 1828, the brand initially sold soaps and cosmetics, eventually expanding to include exquisite fragrances that captivated a growing clientele. Guerlain's reputation grew rapidly, attracting royalty and nobility, including Queen Victoria and Empress Elisabeth of Austria-Hungary. The creation of "Eau de Cologne Impériale" for Empress Eugénie solidified Guerlain's status as the "Official Perfume Supplier to the Imperial Court."

Over generations, Guerlain was passed down within the family, with each successor adding their own touch of creativity and innovation to the brand. Perfumers like Aimé Guerlain, Jacques Guerlain, and Jean-Paul Guerlain continued the legacy by crafting iconic scents like "Jicky," "Mitsouko," and "Shalimar." These fragrances became timeless classics, celebrated for their unique blends of natural and synthetic essences.

In 1994, Guerlain was acquired by the LVMH group, marking a new chapter for the brand. Today, Thierry Wasser carries on the legacy as the current perfumer, introducing modern creations like "La petite Robe Noire." With a history rooted in craftsmanship and innovation, Guerlain remains a symbol of elegance and luxury in the world of perfumery.

Guerlain

Shalimar EDP

I have a DEEP love for Shalimar and Samsara … not only do they refresh me but fuel my inner sparks

User-8340323

Experience the essence of luxury with our exquisite line of perfumes. Indulge in the artistry of our captivating scents, carefully crafted to elevate your senses and evoke a sense of sophistication. Each fragrance is a unique blend of opulent notes that will transport you to a world of elegance and style. Discover the scent that speaks to your personality and essence, and make a statement with our prestigious collection of perfumes.

Love Cosmetics

Love's Deep Earthy Musk

Loves Deep Earthy Musk is by far the best Musk ever!!!!! It's very natural and uplifting, almost magical,it has been my favorite scent for my entire life <br/>I do hope they reintroduce it again, I am sure to purchase many more bottles and never be without it again 🤲

Donna

Tom Ford, a renowned personality in the fashion industry, has been a prominent figure for decades with his creations often gracing the red carpet and the pages of top fashion magazines like "Vogue." His journey into the world of fragrances dates back to the early 1990s.

In 1992, Ford assumed the role of creative director at Gucci, giving him control over the brand's perfume line. He later expanded his influence by taking on a similar role at Yves Saint Laurent in 2000. One of his notable contributions during this time was the creation of "M7," a groundbreaking men's fragrance that popularized the oud note in a more widespread manner.

In 2005, Ford collaborated with Estée Lauder to establish his own brand, Tom Ford Beauty. Under this label, he introduced two fragrance series: the more affordable "Signature" line, starting with the launch of "Black Orchid" in 2006, and the high-end "Private Blend" collection in 2007. The latter has become a favorite among perfume enthusiasts, featuring captivating scents like "Tobacco Vanilla," "Tuscan Leather," and "Oud Wood."

While Ford's fragrance bottles exude simplicity in design, his marketing campaigns are anything but modest. For instance, the debut of "M7" was accompanied by a striking advertisement featuring a fully nude Samuel de Cubber, creating a buzz in the industry.

Tom Ford

Ombré Leather (2018) EDP

Not much elucidation required. A top-notch refined, masculine leather scent with gentle, velvety florals and a captivating aura.

GhostlyGoddess

This perfume brand is known for its distinctive and captivating scents that evoke a sense of luxury and sophistication. Each fragrance is carefully crafted with high-quality ingredients to create a unique and memorable olfactory experience. From floral and fruity to woody and oriental, there is a scent to suit every taste and occasion. Explore the world of this renowned perfume brand and discover a new signature scent that will leave a lasting impression.

Jeroboam

Haŭto

This fragrance is quite artificial and contains a higher proportion of synthetic components rather than natural ones. It exudes a blend of sugary, fruity, flowery, and piquant notes.

BlizzardBlastX

The renowned Spanish fashion label Zara captivates with its modern designs and exceptional customer service. Specializing in fast fashion, Zara offers a wide range of textiles, shoes, and accessories for women, men, and children.

Established in 1975 in A Coruña, Spain, Zara quickly expanded with stores in Portugal, the USA, and later in Germany. Unlike traditional fashion houses, Zara collaborates with researchers to identify global trends and swiftly adapt them to its collections. This swift production process, often taking just a month from design to sale, allows Zara to offer quality products at moderate prices, thanks in part to manufacturing in Europe.

While Zara's success is built on its agility in responding to trends, the brand has faced criticism for labor practices, including reports of poor working conditions and child labor. Additionally, Zara has been accused of unethical practices such as racism, monitoring employees, using carcinogenic materials, and alleged tax evasion.

Zara products are exclusively available in its own stores, department store sections, and online, with over 2,000 outlets in more than 90 countries.

Zara

Morning Sunray in Sevilla

Lush, tangy, golden grass and dried grass, damp from raindrops, with a hint of boozy warmth reminiscent of a blend of fragrant plants. This is the vibrant greeting that beckons me in.

BlitzKrieg

Parfums de Marly is a prestigious French fragrance brand offering a variety of scents that embody unique olfactory experiences and a touch of French sophistication. Founded by Julien Sprecher in 2009, the brand seeks to pay homage to the aromatic 18th century with its exquisite perfumes. During this era, scents played a pivotal role in social interactions, particularly in aristocratic circles and the court of King Louis XV, where only distinctive and natural fragrances were favored. The name "Parfums de Marly" is a nod to the fragrant legacy of the French Château de Marly, symbolizing the essence of the 18th century.

The brand's fragrances are crafted from natural ingredients, resulting in captivating blends such as citrus and pepper in "Galloway", mandarin and wood in "Percival", or fern, vanilla, and almond notes in "Pegasus". 

For women, the Delina series is a popular choice, offering scents like lychee, Turkish rose, rhubarb, lily of the valley, and peony in "Delina" or bergamot, pear, lychee, amber, and bergamot in "Delina Exclusif".

Men can explore a diverse range of scents from "Parfums de Marly" including "Sedley", "Kalan", "Layton", and "Godolphin", catering to a wide range of preferences from masculine to playful to oriental.

Apart from the captivating fragrances sourced from around the world, the brand's signature glass bottles (available in 75 ml or 125 ml) stand out with a consistent design featuring two horses, a beloved symbol by founder Julien Sprecher. The silver or gold caps add an elegant touch, while variations in bottle colors and materials help preserve the fragrance's essence until its first application.

Parfums de Marly

Hamdani

Incredibly repulsive - a blend of smoked salmon, engine lubricant & rawhide. Slightly medicinal as well. Perhaps the most offensive fragrance I've encountered.

PixelWarrior

Shiny leather boots and disinfectant cream. A technician cleanses their grimy hands with honey and sandalwood cleanser.

ViperVenom

The story behind the exclusive fragrances of the brand "Tiziana Terenzi" is truly unique. It all started with Guglielmo Terenzi founding a wax factory in Catalonia in the 1980s, specializing in crafting candles for various occasions with a focus on unrivaled quality and design. His son Evelino Terenzi took the company to new heights by developing safe, food-grade candle wax for handling candles. Paolo and Tiziana Terenzi continued this legacy, infusing their passion for beauty into the brand, ultimately venturing into the opulent world of fragrances.

Today, Tiziana Terenzi offers a range of fragrances in elegantly designed round or square bottles, predominantly in black and gold hues, creating a cohesive and recognizable collection. The scents themselves are diverse, from floral notes of lilac, vanilla, and peach in "Afrodite" to the rich blend of leather, saffron, honey, and lemon in "Chimaera" and the exotic mix of jasmine, orange, amber, and sandalwood in "Spirito Fiorentino."

A standout quality of "Tiziana Terenzi" is that almost all of their 80+ fragrances are unisex, appealing to both men and women with an array of aromas to suit every preference.

Tiziana Terenzi

Orza

Exciting beginning with crisp apple, succulent plum, vibrant raspberry, and creamy coconut. As it unfolds, a bouquet of rose emerges, followed by benzoin, vanilla, and savory ambergris.

BlazeFury

The Sultanate of Oman, located on the southeastern coast of the Arabian Peninsula, was under the rule of Sultan Qaboos bin Said from 1970 to 2020. During his reign, the country transitioned from nomadic traditions to a more modern society with a focus on trade relations with the West. Oman boasts an impressive healthcare system, a stable social safety net, and a comprehensive education policy.

In the early 1980s, Sultan Qaboos decided to revive the tradition of perfume production in Oman, dating back to the 9th century, and establish a signature fragrance for his Sultanate. Thus, Amouage, meaning "wave" in Arabic, was founded in the capital city of Muscat, generously funded by the state treasury.

Renowned French perfumer Guy Robert was enlisted to create the ultimate Omani scent, incorporating local essences such as myrrh, rosewater, and Omani frankincense. The result was the iconic Amouage Gold fragrance.

Amouage fragrances not only provided a sense of national identity for the people of Oman but also served as esteemed representations of the country. Often exchanged as gifts during state visits or found in hotel rooms, these perfumes earned the moniker "The Gift of Kings."

In recent years, Amouage has expanded its reach to the international market, offering a touch of luxury that brings the opulence of Oriental perfumery and the rich heritage of Arabian nights to European consumers. Through this prestigious brand, the essence of Oriental perfume culture has made its way onto global skin and into the hearts of fragrance enthusiasts worldwide.

Amouage

Reflection Woman EDP

Fresher and more verdant than flowery to my senses and on my skin, this fragrance appears to be delectable for both ladies and gents. Charming and serene.

NeonNebulaK

Chilled and tangy like a fruit outdoors on a snowy day. Incredibly vibrant in color.

Stark

Discover the essence of luxury with a captivating fragrance collection that embodies elegance and sophistication. Unveil a world of scents that exude charm and allure, crafted with the finest ingredients in exquisite bottles. Experience the art of perfumery like never before, as each fragrance tells a unique story and leaves a lasting impression. Indulge in the opulence of our signature scents and elevate your senses to a whole new level of refinement. Choose a scent that resonates with your personality and embrace the transformative power of fragrance. Elevate your daily routine with a touch of elegance and let your scent speak volumes about your style and individuality.

Maison Tahité

Cacao²

Yummy! I'm not a huge foodie fan, but I couldn't resist grabbing this right away, especially considering the cost! ($120 USD) Unique gourmet treat that will satisfy a wide range of tastes!

MidnightMage

Experience the essence of luxury with our exquisite line of fragrances. Our perfumes are crafted with the finest ingredients to evoke emotions and memories with every spritz. Elevate your senses and indulge in the art of scent with our captivating collection.

N.C.P.

Olfactive Facet 301 - Jasmine & Sandalwood

Stunning hyperrealistic jasmine blossom fragrance. Intoxicating, vibrant, and clean. Ideal for blending with other scents.

MetalMarauder

Discover a luxurious fragrance line that captivates the senses and embodies elegance and sophistication. Explore a unique collection of scents that evoke charm and allure, crafted with the finest ingredients to create an experience that is truly unforgettable. Experience the essence of luxury and style with our exceptional perfume brand.

Francesca Dell'Oro

Vanille 12:00

Perfect fusion of luscious fruity and indulgent gourmand scents. Light and luscious, not cloying, but vibrant and delectable. Authentically natural, dispelling my initial synthetic concerns.

NeonVortex

Experience the essence of luxury and elegance with our refined collection of fragrances. Indulge in the unique blend of scents crafted to captivate your senses and leave a lasting impression. Embrace the sophistication and allure of our perfume brand, where each bottle holds a masterpiece waiting to be discovered. Elevate your everyday moments with the touch of luxury that only our perfumes can provide.

Sucreabeille

Cersei EDP

Not my cup of tea. Overabundance of thyme.

DuskDragon

Discover the essence of luxury and elegance with our exquisite line of fragrances. Experience the captivating aromas and indulgent scents that will transport you to a world of sophistication and glamour. Elevate your senses with our carefully crafted perfumes that are designed to leave a lasting impression. Embrace the allure of our brand and immerse yourself in a world of beauty and prestige.

Christian Provenzano

Iris d'Orient

A fascinating fragrance that transforms four times as it lingers on the skin. Truly enchanting!

Nabeel Perfumes, a prestigious fragrance house in the United Arab Emirates, has been creating exquisite scents since 1969. Originally established in Yemen and later moving its operations to the UAE in 1990, Nabeel Perfumes has become one of the top perfume manufacturers in the region. Specializing in both oriental and western fragrances, Nabeel offers a wide range of captivating scents that cater to diverse tastes and preferences. Experience the essence of luxury and elegance with Nabeel Perfumes.

Nabeel

Dubai - Oud

A softly suede and arid, eastern zesty-woody fragrance, with a hint of fruity and sharp, fiery zesty/wild beginning. Provocative!

StarkStriker

In the world of perfumes and cosmetics, where big brands dominate, Jo Malone stands out as a beacon of exclusivity and excellence. Founded by the entrepreneur Jo Malone, the brand offers a range of luxurious fragrances, shower gels, bath oils, and skincare products that are primarily available in select stores in the USA and the UK, giving them an air of sophistication and rarity.

The brand's journey began with Jo Malone's boutique facial care clinic in Chelsea, which quickly gained a loyal following for its personalized approach to skincare. Inspired by her success, Jo ventured into the world of fragrances, creating unique scents with the help of perfumers in Grasse, France. Her first creation, the "Nutmeg & Ginger" bath oil, marked the beginning of her foray into the world of perfumery.

A pivotal moment came in 1991 with the launch of the iconic "Lime Basil & Mandarin" fragrance, which catapulted Jo Malone to fame and fortune. Known for her innovative concept of "Fragrance Combining," Jo encouraged customers to mix and match scents to create their own personalized perfumes, revolutionizing the industry.

Despite being acquired by Estée Lauder in 1999, Jo Malone remains at the helm of creativity, continuing to innovate and inspire. With a wide range of fragrance lines and products to choose from, customers can customize their scent experience to reflect their individual tastes and preferences.

From the exquisite packaging to the long-lasting formulations, Jo Malone's products exude luxury and sophistication, making each purchase a special and delightful experience. As a pioneer in the world of perfumery, Jo Malone continues to redefine luxury with her timeless creations, ensuring that each customer feels unique and cherished.

Jo Malone London

Pomegranate Noir (Cologne)

The strong scent of "masculine fragrance" overwhelms my senses. A subtle tangy undertone is the only hint of pomegranate I can detect.

ShadowSoulX

Discover a luxurious fragrance collection from a sophisticated perfume brand that exudes elegance and style. Experience the exquisite blend of aromatic notes that evoke memories and emotions, and create a lasting impression wherever you go. Elevate your senses with this captivating range of scents that are designed to make you feel confident and alluring. Unleash the power of fragrance to enhance your mood and leave a lasting impact on those around you.

Malin + Goetz

Dark Rum (Perfume Oil)

The fragrance of milk and plum combines to exude a scent reminiscent of cherimoya, though regrettably, there is a scarcity of rum notes in this blend.

CrimsonClaw

For many years, Montblanc has stood as a symbol of excellence in the luxury market as a leading creator of premium writing instruments. While the brand also offers meticulously crafted wristwatches, leather goods, and jewelry, its primary focus remains on producing exquisite ballpoint pens and fountain pens bearing the iconic Montblanc emblem.

Established in Berlin at the dawn of the 20th century, Montblanc's origins trace back to the visionary August Eberstein, who drew inspiration from fountain pen production in the US and sought to bring this expertise to Germany in 1906. With the support of investors and a series of patented innovations, the foundation was laid for the "Simplo Filler Pen Co. Max Koch," founded in 1907. Initially replicating American designs, the company's exceptional fountain pens quickly gained recognition, leading to collaborations with renowned brands like "Faber-Castell" and "Staedler," eventually paving the way for Montblanc's own distinctive models featuring the iconic star logo, established as a registered trademark in 1913.

Today, Montblanc offers a diverse range of prestigious writing instruments such as the "Meisterstück," the "UNICEF Editions," the "Diva Line," and "Bohème," each showcasing subtle variations in materials, design, and functionality while consistently upholding the brand's renowned standards of quality and durability that endure for generations.

Employing a workforce of over 3,000 individuals, with approximately 30% based at the brand's Hamburg headquarters, Montblanc has been under the ownership of "Alfred Dunhill, Ltd." since 1977, becoming part of the esteemed "Compagnie Financière Richemont SA" family, alongside its esteemed range of writing instruments, timepieces, jewelry, and leather accessories.

Montblanc

Legend EDT

An elegantly unisex fragrance. Bright citrus and herbaceous lavender notes lead the way, eventually giving way to a warm tonka bean aroma after a few hours. Perfect for wearing in a professional setting.

StarStruck

Experience the essence of luxury with fragrances by this renowned perfume house. Indulge in a symphony of exquisite scents crafted with precision and passion. Elevate your senses and embrace the allure of these exceptional perfumes.

Lorenzo Pazzaglia

Extreme Passion

Following a delightfully ripe and luscious tropical fruit-sweet introduction, this aromatic fruity-floral scent for Summer transitions into a velvety resinous-woody foundation.

Pierre Guillaume

A novel fragrance created by Pierre Guillaume for both women and men, launched in 2025.

27.1 Le Chant des Sirènes

Sandalwood

Resin with a warm, ambery and spicy fragrance

Opoponax

Starfruit

Almond wood is a warm and creamy fragrance note that combines the rich, nutty scent of almonds with the woody undertones of cedarwood. It adds a comforting and luxurious touch to any perfume composition.

Almond wood

Rock samphire, also known as sea fennel, is a unique fragrance note that blends the earthy freshness of juniper with the salty tang of the ocean. It adds a refreshing and invigorating element to perfumes, reminiscent of coastal cliffs and seaside breezes.

Rock samphire

Dalbergia leaf is a subtle and aromatic note that exudes a woody and slightly floral scent. It adds a touch of sophistication to fragrances, creating a warm and inviting aura.

Dalbergia leaf

In 2025, a brand-new fragrance by Pierre Guillaume was launched, suitable for both women and men.

20.2 Église de Velours

A family of soft sensual and tenacious scents, generally synthetic, slightly reminiscent of animal musk

Musk

An incense-like resin with an ambery, mossy and slightly liquorice fragrance

Myrrh

Hinoki cypress is a fresh and woody fragrance note derived from the Japanese cypress tree. It offers a calming and grounding scent with hints of citrus and pine, reminiscent of a tranquil forest setting.

Hinoki cypress

Frankincense resin is a warm and spicy note, known for its rich, aromatic, and balsamic scent. It adds a touch of sophistication and depth to fragrances, creating a sense of tranquility and spirituality.

Frankincense resin

Silk is a luxurious and smooth perfume note that evokes elegance and sophistication. It adds a soft and subtle touch to fragrances, creating a delicate and refined scent.

Silk

Introducing a fresh fragrance created by Pierre Guillaume for both men and women, launched in the year 2024. This delightful perfume offers a blend of sweet and synthetic notes that are sure to captivate your senses.

21.1 Orchidivy

Smell of red fruits, both sweet and juicy

Raspberry

Green scent reminiscent of crumpled leaves

Powerful white floral scent with slightly green and spicy accents

Gardenia

Tomato leaf is a fresh and green note in perfumery, reminiscent of the plant's crisp and slightly earthy aroma. It adds a unique and vibrant touch to fragrances, often used to bring a natural and invigorating quality to scents.

Tomato leaf

Vanilla absolute is a rich and sweet fragrance note that can add warmth, sweetness, and depth to a perfume composition. It is often described as creamy, smooth, and comforting, with a hint of exotic sweetness that can be both comforting and seductive.

Vanilla absolute

Tonka bean absolute is a warm, sweet, and slightly spicy note used in perfumery. It adds depth, richness, and a creamy vanilla aroma to fragrances.

Tonka bean absolute

Sweet smell of dried grass, straw and tobacco

Introducing a newly launched fragrance by Pierre Guillaume designed for both women and men, introduced in 2024. This exquisite perfume boasts a delightful blend of creamy and fresh notes that will surely captivate your senses.

Le Musc & La Peau (Extrait de Parfum)

A rich combination of vanilla, spices and resins

Amber

An herb used in cooking with fresh, camphoric facets

Rosemary

Rich floral scent with jasmine and spicy accents

Ylang-ylang

Cedar is a warm, woody and aromatic note commonly used in perfumery. It adds a sense of depth and sophistication to a fragrance, with a grounding and comforting quality.

Cedar

Sweet and creamy smell reminiscent of hot milk

Milk

In 2024, a fresh fragrance created by Pierre Guillaume for both women and men has been launched.

Stælios

Precious woods refer to highly valued and luxurious types of wood used in perfumery, such as oud, sandalwood, and cedarwood. These notes add warmth, depth, and sophistication to a fragrance, creating a rich and elegant olfactory experience.

Precious woods

Kingwood is a precious wood note derived from the Brazilian kingwood tree. It exudes a warm, rich, and slightly sweet aroma with hints of tobacco and leather, which adds depth and complexity to perfumes.

Kingwood

Davana

Russian leather is a rich and robust scent evoking the rugged terrain of the Russian wilderness. It features a combination of smoky, woody, and animalic notes, creating a distinct and powerful fragrance experience.

Russian leather

Ashanti pepper leaf

Introducing a fresh fragrance created by Pierre Guillaume, designed to appeal to both women and men, and launched in 2024. This perfume features a delightful blend of zesty citrus notes paired with warm, aromatic spices, creating a vibrant and inviting aroma.

Bonheur du Jour

Citrus fruit with aromatic and slightly floral facets

Bergamot

Citrus fruit with a sparkling, slightly fruity fragrance

Mandarin orange

A resin with a warm scent of amber and leather

Labdanum

Dried leaves with a woody, earthy, powerful scent

Patchouli

Leaves and branches of the orange tree. Floral, citrus and slightly green scent.

Petitgrain

Aromatic, invigorating and slightly camphoric smell

Thyme

Cinnamon

Black pepper is a spicy and aromatic note often used in perfumery to add warmth and depth to fragrances. It adds a touch of sophistication and zing to any composition, creating a bold and sensual experience.

Black pepper

A citrus fruit with a juicy and tangy fragrance

Lemon

Small Japanese citrus fruit with a tangy and sparkling scent

Yuzu

Galbanum

A fruity, floral and slightly herbal scent

Tagetes

Vervain is a herbaceous note known for its fresh, bright, and slightly lemony aroma. It adds a crisp and invigorating quality to fragrances, making them feel uplifting and energizing.

Vervain

Provençal lavender is a fragrant note derived from lavender plants grown in the Provence region of France. It has a fresh, herbaceous, and slightly sweet aroma, often described as calming and soothing.

Provençal lavender

Introducing a fresh fragrance from Pierre Guillaume, suitable for both men and women, set to launch in 2023. This captivating perfume boasts a delightful blend of floral and sweet notes. Currently in the production phase, this scent promises to be a splendid addition to your fragrance collection.

31.1 L'Air & L'Eros

Tonka bean

Lilac

White chocolate is a rich and creamy gourmand note with a sweet and indulgent aroma. It adds a luxurious and comforting touch to fragrances, reminiscent of dessert and coziness.

White chocolate

An innovative fragrance created by Pierre Guillaume designed for both ladies and gentlemen, introduced in 2023. This perfume features a refreshing green-spicy aroma, currently undergoing the production process.

14.2 Costume Liquide

Aromatic herb with slightly aniseed and spicy facets

Basil

Gentle floral note slightly reminiscent of rose

Peony

A powdery, slightly woody fragrance with floral nuances of violet

Iris

Pepper

Floral note with powdery and green accents 

Violet leaf

Haitian vetiver is an earthy and smoky note derived from the vetiver grass native to Haiti. It adds depth and complexity to fragrances, with its woody and slightly sweet aroma.

Haitian vetiver

Pierre Guillaume's latest fragrance, designed for both women and men and set to debut in 2023, exudes a luscious and creamy sweetness. This alluring scent is currently in the final stages of production, awaiting its eagerly anticipated release.

AromaVerse

AromaVerse

Ciel d'Airain Pierre Guillaume

Main Accords

Fragrance Pyramid

Top Notes

Middle Notes

Base Notes

Classification

Season

Gender

Ratings

Scent

Longevity

Sillage

Reviews

Popular by Pierre Guillaume

Latest Releases

Latest Reviews

Shalimar EDP

Love's Deep Earthy Musk

Ombré Leather (2018) EDP

Haŭto

Morning Sunray in Sevilla

Hamdani

Hamdani

Orza

Reflection Woman EDP

Reflection Woman EDP

Cacao²

Olfactive Facet 301 - Jasmine & Sandalwood

Vanille 12:00

Cersei EDP

Iris d'Orient

Dubai - Oud

Pomegranate Noir (Cologne)

Dark Rum (Perfume Oil)

Legend EDT

Extreme Passion