1st - Gold 
January 
February 
March 
April 
May 
June 
July 
August 
September 
October 
November 
December 
Capricorn - Garnet 
Aquarius - Amethyst 
Pisces - Aquamarine 
Aries - Diamond 
Taurus - Emerald 
Gemini - Pearl 
Cancer - Ruby 
Leo - Peridot 
Virgo - Blue Sapphire 
Libra - Opal 
Scorpio - Topaz 
Sagittarius - Tanzanite 
Black Diamond vs Tanzanite
Which Gemstone Should You Choose?
Choosing between Black Diamond and Tanzanite can be challenging due to their unique colours, brilliance, and value. While both are popular for fine jewellery, they differ greatly in hardness, durability, and market value.
This Black Diamond vs Tanzanite comparison guide explains the key differences to help you select the perfect gemstone for rings, necklaces, or earrings.
Black Diamond vs Tanzanite: Quick Comparison
| Feature | Black Diamond | Tanzanite |
|---|---|---|
| Mineral Family | Carbon (Diamond) | Zoisite (Calcium Aluminium Silicate) |
| Hardness | 10 – Extremely durable | 6 – 7 – Softer, delicate wear |
| Value | High; luxury and investment jewellery | Moderate to high; fine blue gemstones |
| Best For | Engagement rings, diamond jewellery, investment pieces | Tanzanite jewellery, statement pieces, occasional wear |
| Professional Guides | Diamond Buyer’s Guide | Tanzanite Buyer’s Guide |
Black Diamond Features, Colour & Investment Value
Black Diamonds are carbon-based gemstones with a unique opaque black hue and metallic-like shine. They are extremely hard, ranking 10 on the Mohs scale, making them highly durable for everyday wear.
Origins & History:
Black Diamonds come from Brazil and Africa, often treated to enhance colour. They are increasingly popular in luxury engagement rings and designer diamond jewellery.
Price Guide (per carat):
R5,000 – R120,000 depending on quality, size, and treatment.
Tanzanite Features, Colour & Durability
Tanzanite is a stunning blue-violet gemstone found only in Tanzania. Its vibrant colour ranges from rich royal blue to violet-blue, creating a luxurious option for fine jewellery.
Origins & History:
Tanzanite is rare and highly prized; it was discovered in the 1960s in the Mererani Hills of Tanzania. Unlike Black Diamonds, tanzanite is softer (Mohs 6–7) and requires careful handling.
Price Guide (per carat):
R3,500 – R50,000 depending on quality and size.
Black Diamond vs Tanzanite: Detailed Technical Comparison
| Feature | Black Diamond | Tanzanite |
|---|---|---|
| Chemical Composition | Pure carbon; may be treated to enhance black colour | Calcium aluminium silicate (Zoisite) with vanadium traces |
| Colour | Opaque black, metallic sheen | Vivid blue to violet-blue |
| Hardness (Mohs) | 10 – Extremely durable | 6 – 7 – Requires careful handling |
| Refractive Index | 2.417 – 2.419 | 1.691 – 1.700 |
| Specific Gravity | 3.52 | 3.35 |
| Clarity & Inclusions | Opaque; inclusions not visible; metallic surface | Typically eye-clean; minor inclusions may appear |
| Origin | Brazil, Central Africa | Mererani Hills, Tanzania |
| Treatment | Commonly treated with high temperature or irradiation | Typically heat-treated to enhance blue colour |
| Best Use | Luxury diamond jewellery, investment rings | Tanzanite jewellery, statement rings, occasional wear |
Black Diamond vs Tanzanite: Colour, Durability & Care Tips
Colour Comparison:
- Black Diamond: Deep opaque black, metallic lustre; ideal for white and black diamond jewellery.
- Tanzanite: Vivid blue-violet; striking in blue gemstones and tanzanite jewellery.
Hardness & Durability:
- Black Diamond: Mohs 10 – perfect for rings and jewellery that are worn daily.
- Tanzanite: Mohs 6–7 – softer; best for necklaces, earrings, or pieces with protective settings.
Care Tips:
- Black Diamond: Very durable; clean with mild soap, avoid harsh abrasives.
- Tanzanite: Avoid knocks and heat; clean gently with warm water and soft cloth.
Black Diamond vs Tanzanite: How to Tell Them Apart
💡 Tip: Check hardness, transparency, and brilliance. Black Diamonds are opaque with metallic sheen; Tanzanites are translucent with vivid blue-violet colour.
Black Diamond Summary
- Hardness: Mohs 10 – extremely durable
- Colour: Opaque black, metallic lustre
- Refractive Index: 2.417 – 2.419
- Inclusions: Not visible; treated surface
- Care: Suitable for daily wear; clean gently
Tanzanite Summary
- Hardness: Mohs 6–7 – softer, delicate
- Colour: Blue to violet-blue
- Refractive Index: 1.691 – 1.700
- Inclusions: Minor; generally eye-clean
- Care: Handle carefully; avoid knocks and extreme heat
Buying Tips
- Always request certified gem reports for Black Diamonds and Tanzanite.
- Confirm treatments; Black Diamonds often irradiated or heat-treated, Tanzanite usually heat-treated.
- Consider jewellery setting: Black Diamonds can be set in daily wear rings; Tanzanites need protection due to softness.
- Browse our Black Diamond Collection and Tanzanite Collection.
Which Gemstone Should You Choose?
- Black Diamond: For investment, luxury, and extremely durable white gemstone jewellery.
- Tanzanite: For vivid blue gemstones, statement jewellery, and occasional wear.
Both are striking, but understanding their differences ensures the right choice for your style and budget.
Black Diamond vs Tanzanite FAQ’s
Can Black Diamond be scratched?
Extremely rare; Mohs 10 hardness makes them highly scratch-resistant.
Is Tanzanite suitable for everyday rings?
Not recommended; softer hardness requires protective settings.
Are Black Diamonds treated?
Yes, commonly irradiated or heat-treated to enhance colour.
Does Tanzanite change colour?
Tanzanite can show different shades under different lighting due to pleochroism.
Which gemstone is better for investment?
Black Diamond is considered an investment-grade luxury gemstone.
Can Black Diamond and Tanzanite be combined in jewellery?
Yes, they complement each other beautifully in statement rings or pendants.
COMPARE GEMSTONES WITH CONFIDENCE
Gemstone Comparison Guides
Choosing between two beautiful gemstones can be challenging. Our professional Gemstone Comparison Guides help you clearly understand the differences between popular gemstones so you can make a confident and informed choice.
Each comparison explores the key factors that influence gemstone quality and value, including colour, clarity, durability, rarity and typical treatments. You will also learn how similar-looking gemstones differ in appearance, composition, hardness and more.
HERE IS ALL THE PROFESSIONAL INFORMATION YOU NEED
Gemstone Buyer's Guides
Buying a gemstone should be exciting — but understanding quality, rarity and value is essential before making the right choice. Our professional Gemstone Buyer’s Guides help you understand how colour, clarity, cut and treatments influence the beauty and value of different gemstones.
Each guide explains the key quality factors used by gemologists, including gemstone composition, colour grading, natural inclusions, treatments and origin. You will also learn how these factors affect rarity, durability and market value.
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