Precious & Semi-Precious Gemstones: The Complete Buyer's Guide
By the Expert Gemologists at Rasikh Gems & Jewellers - Certified by GIA, GRS & IGI | Est. 1970
Whether you're buying your first ring set with a coloured stone, seeking a gem for astrological benefit, or investing in rare precious specimens, this guide covers everything you need to know - from understanding the difference between precious and semi-precious categories, to identifying authentic stones, choosing by birth month, and buying with confidence.
Rasikh Gems & Jewellers has been guiding buyers across Dubai, the UAE, India, and the US since 1970. Our certified gemologists bring you this reference so you can make decisions based on knowledge, not guesswork.
What Are Precious and Semi-Precious Stones?
The terms precious and semi-precious have been used in the gem trade for over a century to distinguish rarity and value - though today, many rare semi-precious varieties command prices that rival or exceed the classical four.
The Four Traditional Precious Gemstones
Historically, only four have been classified as precious:
- Diamond - The hardest natural substance on earth, prized for brilliance and fire
- Ruby - A red variety of corundum; among the most valuable stones per carat in the world
- Emerald - The deep green beryl associated with royalty and renewal
- Sapphire - Corundum in every colour except red; most celebrated in blue
Everything else - aquamarine, amethyst, topaz, opal, amber, malachite, and hundreds more - falls under the semi-precious category. This does not mean they are less beautiful or less valuable. A fine alexandrite or a rare padparadscha sapphire can rank among the most expensive gems on earth.
Stones by Colour: A Complete Reference
One of the most common ways buyers search is by colour. Here is a comprehensive guide to popular gems by colour family.
Blue Stones
Blue is one of the most beloved colours in Gemstone jewellery.
- Sapphire - The classic blue gem; deep cornflower blue is the most prized
- Aquamarine - A pale to medium blue beryl, the March birthstone; popular for elegant aquamarine jewellery
- Blue Topaz - Widely used in silver rings for both men's and women's styles
- Lapis Lazuli - Deep midnight blue with golden pyrite flecks; treasured since ancient Egypt
- Blue Zircon - Brilliant and affordable; a popular diamond alternative
Buyer tip: When shopping for blue stones, always check for heat treatment. Natural, unheated blue sapphires carry a significant premium and should come with a GIA, GRS, or IGI certificate.
Red Stones
Red carries powerful energy in both jewellery and Vedic astrology.
- Ruby - The king of red precious gemstones; associated with the Sun in Vedic astrology
- Red Coral (Moonga) - Worn for Mars energy; a staple in astrological recommendations
- Red Spinel - Often mistaken for ruby historically; exceptional brilliance
- Garnet - Deep red semi-precious variety available across a wide price range
- Red Tourmaline (Rubellite) - Vivid red stones ideal for contemporary jewellery
Buyer tip: Ruby price varies enormously based on origin (Burmese stones command the highest premiums), colour saturation, and treatment status. Always request a certificate before purchase.
Green Gemstones
Green ranges from the intensely rare to the accessibly priced.
- Emerald - The most valued green precious stone; Colombian specimens are considered finest
- Tsavorite Garnet - A vivid green rival to emerald; far rarer
- Alexandrite - Shifts from green in daylight to red-violet under incandescent light
- Peridot - Olive to bright green; the August birthstone
- Malachite - Rich banded green; popular in statement pieces
- Jade (Jadeite) - Deep imperial green; among the most expensive in Asian markets
- Green Tourmaline - Affordable, available in various shades
Pink Gemstones
Soft and romantic, pink is among the most sought-after in contemporary design.
- Pink Sapphire - A pink precious gemstone in the corundum family
- Rose Quartz - One of the most popular pink-coloured varieties; widely available
- Morganite - Peachy-pink beryl; popular for engagement rings
- Rhodonite - Deep pink with black veining; distinctive character
- Pink Tourmaline - Vivid pink for rings and pendants
Purple Gemstones
Purple has long been the colour of royalty and spiritual wisdom.
- Amethyst - The most popular purple variety; the February birthstone and widely used in Vedic astrology
- Purple Sapphire - A rare member of the corundum family
- Charoite - Unusual swirling purple from Siberia
- Tanzanite - Blue-violet, found only near Mount Kilimanjaro
An amethyst ring or amethyst bracelet makes an excellent choice for buyers seeking meaningful, visually striking jewellery at an accessible price point.
Black Gemstones
Bold and dramatic, black gems are increasingly popular in contemporary design.
- Black Onyx - The most common black stone used in jewellery
- Black Tourmaline - Strong protective associations in crystal healing
- Black Diamond - Rare carbonado diamonds; among the most expensive black gems
- Jet - An organic variety formed from fossilised wood; historically used in mourning jewellery
- Obsidian - Volcanic glass; widely used in black jewellery
Yellow and Amber Stones
- Yellow Sapphire (Pukhraj) - One of the most recommended gems in Vedic astrology, representing Jupiter
- Citrine - Warm golden-yellow quartz; affordable and widely loved
- Amber - Fossilised tree resin, not a mineral, but treasured for its warm honey tones
- Yellow Topaz - Brilliant and durable; available from pale to deep golden
Orange and Coral Stones
- Red Coral (Moonga) - One of the nine Navratna stones in Vedic tradition
- Sunstone - Glittering orange feldspar
- Hessonite (Gomed) - A brownish-orange garnet used in Vedic astrology for Rahu
The Navratna: Nine Sacred Gems of Vedic Astrology
The Navratna (nine gems) is a sacred concept in Vedic astrology where nine specific stones are worn together to represent the nine planets. A Navratna jewellery piece is considered highly auspicious.
| Stone | Planet |
| Ruby | Sun |
| Pearl | Moon |
| Red Coral (Moonga) | Mars |
| Emerald | Mercury |
| Yellow Sapphire | Jupiter |
| Diamond | Venus |
| Blue Sapphire (Neelam) | Saturn |
| Hessonite (Gomed) | Rahu |
| Cat's Eye (Lehsunia) | Ketu |
The cat's eye Gemstone displays a sharp moving band of light called chatoyancy. Associated with Ketu, it is believed to offer protection and clarity.
The Most Expensive Gemstones in the World
For buyers interested in investment-grade specimens, here are the most valuable available:
- Blue Diamond - The most expensive gem by carat weight; the rare Oppenheimer Blue sold for over $57 million
- Red Diamond - The rarest colour variant; the costliest stone per carat on earth
- Jadeite - Imperial green jade; the most valuable in Asian markets
- Alexandrite - Fine specimens with strong colour-change rank among the priciest coloured stones per carat
- Ruby (Burmese, unheated) - The most valuable certified coloured stone per carat in the world
- Emerald (Colombian, no oil) - Untreated Colombian specimens are among the rarest gems available
- Padparadscha Sapphire - Rare pink-orange sapphire; among the most coveted precious stones
- Musgravite - One of the least-known rarities; first discovered in Australia
- Benitoite - Found only in California; the rarest gem commercially available
- Tanzanite - Mined within a single square mile on Earth
How to Identify Real Gemtones: A Buyer's Guide
- Gemological Certification The most reliable method. A certificate from GIA, GRS, or IGI confirms identity, treatment status, and origin. At Rasikh Gems, all significant pieces come with third-party certification - non-negotiable for pearls, rubies, sapphires, and emeralds.
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Refractive Index Testing
Every natural stone has a specific refractive index - the way it bends light. A refractometer quickly separates genuine specimens from imitations.
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Specific Gravity
Real gemstones have a specific density. A heavy piece for its size is a positive sign; glass imitations feel noticeably lighter.
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Inclusions Under Loupe
Natural specimens contain inclusions - tiny imperfections formed during growth. Synthetic or glass imitations have different inclusion patterns or none at all. A trained eye can distinguish a natural ruby from a synthetic, or a natural pearl from cultured, by their internal characteristics.
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Thermal Conductivity
Diamonds conduct heat differently from glass or cubic zirconia. Thermal testing pens are a quick screening tool.
Red Flags When Buying
- No certificate for high-value pieces
- Prices dramatically below market for rare stones
- Seller unable to state treatment history
- "Guaranteed results" for astrological stones without a proper consultation
Popular Jewellery Styles at Rasikh Gems
Rings
- Amethyst ring - one of the most popular entry points for coloured gemstone jewellery
- Emerald ring in gold - classic yellow gold settings remain most popular for emerald pieces
- Women's emerald ring - oval and cushion cuts dominate current demand
- Ruby rings - vintage and royal-inspired designs are trending
- Men's silver rings with stones - black onyx, lapis lazuli, and tiger's eye lead this category
Bracelets
- Amethyst bracelets - available in beaded and faceted styles; popular for fashion and crystal healing
- Navratna bracelets incorporating all nine planetary stones
Necklaces & Pendants
- Emerald pendant drops in yellow gold
- Ruby statement necklaces and layered pieces
- Custom-designed jewellery using certified coloured stones
Pricing: What Determines Ruby, Emerald & Sapphire Value?
Price is determined by the "Four Cs" - Colour, Clarity, Cut, and Carat - plus a fifth factor specific to coloured stones: Country of Origin.
Ruby Price Factors
- Origin: Burmese (Mogok) rubies are most expensive gemstone; Thai and Mozambican are priced lower
- Colour: "Pigeon's Blood" red commands the highest premium
- Treatment: Unheated rubies can be 5–10× the price of heated equivalents
- Carat: Price per carat increases sharply above 1ct for fine quality
Sapphire Price Factors
- Royal blue and cornflower blue (Kashmir, Ceylon) are most valuable
- Neelam gemstone used in astrology must be unheated, natural, and of correct weight
- Entry-level natural sapphires are accessible; top Kashmir specimens are among the most expensive on the market
Emerald Price Factors
- Oil treatment: most emeralds are oiled; "no oil" certificates command a significant premium
- Colombian origin with minor inclusions at 2ct+ represents one of the most valuable acquisitions a collector can make
Where to Buy Genuine Gems in Dubai
If you're searching for a reputable gem shop near you in Dubai, here is what to look for:
- Certified gemologists on staff (GIA, GRS, IGI credentials)
- Third-party certification for high-value Gemstones
- Clear treatment disclosure
- Transparent pricing with no pressure selling
- Both Vedic and Western astrology consultation available
- Established track record - decades in business matter
Rasikh Gems & Jewellers has operated since 1970 - over five decades of expertise across Dubai, Ras Al Khaimah, India, and the US. Our certified gemologists and Vedic astrologers offer walk-in consultations and remote birth chart analysis for clients worldwide.
FAQ’s for this blog
Q: What is the difference between precious and semi-precious stones?
A: Ruby, emerald, sapphire, and diamond are traditionally classified as precious stones. Other gemstones are considered semi-precious, although some rare varieties can be equally valuable.
Q: What are the most expensive gemstones in the world?
A: Blue diamonds, red diamonds, fine rubies, emeralds, and Kashmir sapphires are among the world's most valuable gemstones.
Q: How can I tell if a gemstone is real?
A: The best way is through certification from trusted laboratories such as GIA, IGI, or GRS.
Q: Which gemstone should I wear according to my zodiac sign?
A: The right gemstone depends on your birth chart and planetary positions. Professional consultation is recommended.
Q: What is Navratna?
A: Navratna is a combination of nine gemstones representing the nine planets in Vedic astrology.
Q: Are natural pearls available today?
A: Yes, but they are rare. Most pearls available today are cultured pearls, which are also considered genuine.
Q: What is the Cat's Eye stone used for?
A: Cat's Eye is associated with Ketu in Vedic astrology and is believed to offer protection and spiritual growth.
Q: What is the difference between Ruby and Red Coral?
A: Ruby is linked to the Sun, while Red Coral is associated with Mars. Both serve different astrological purposes.
Q: What are birthstone gemstones?
A: Birthstones are gemstones associated with specific birth months and are believed to bring positivity and good fortune.
Q: Why choose certified gemstones?
A: Certified gemstones provide assurance of authenticity, quality, and value, helping buyers make informed decisions.
