which is the most expensive gemstone ?

Most expensive gemstone:  
- Diamonds are considered the hardest and most valuable gemstone due to rarity, durability, and market demand.  

Note: Informational purposes only; value may vary based on quality and market conditions.

Diamond gemstone:  
- Hardest natural gemstone, composed of carbon.  
- Available in various colors; saturated colors are rarer and more valuable.  
- Used in jewelry for durability, everyday wear, and special occasions.  

Note: Informational content only; value varies with quality and market.  

Alexandrite:  
- Alongside rubies and emeralds, high-quality alexandrites are among the most costly gemstones.  
- Sizes >4cts: Burmese rubies more rare; <1cts: alexandrites often cost more than rubies and emeralds.  
- Extremely rare stones under 0.5ct may cost thousands; >1ct may retail for multiples.  

Note: Market prices vary; informational purposes only.

Summary of gemstone experience:  
- Each gemstone corresponds to a specific planet.  
- Wearing gemstones as per planetary guidance may provide positive effects and protect from malefic influences.  
- Nine planets: Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn, Rahu, Ketu.  

Note: Informational content; personal experience may vary.

Most expensive gemstones:  
- Yellow Sapphire, Blue Sapphire, Ruby, Red Coral, and other precious gemstones.  
- Always choose pure and natural gemstones for astrological purposes; high-quality stones are rare.  

Note: Informational purposes only; gemstone quality should be verified.

Top 10 rarest gemstones on Earth:  
1. Poudretteite – discovered 1960s, Quebec, Canada  
2. Tanzanite – Mount Kilimanjaro, Tanzania  
3. Benitoite – San Benito River, California, USA  
4. Grandidierite – Madagascar  
5. Dark Opal – Australia  
6. Red Beryl – Utah, USA  
7. Jadeite – rare deep green, highly valuable  
8. Taaffeite – discovered 1945, extremely rare  
9. Alexandrite – rare color-changing stone  
10. Painite – Guinness Book confirms as rarest mineral; only two known for decades  


Note: Informational purposes only; gemstone quality should be verified.