Judging by what celebrities wear on the red carpet, luxury cocktail rings continue to reign supreme. If you’re looking to bring some sparkle to your favorite Valentine, consider giving her (or him?) a ring with gems of grand proportions, one that’s a fashion statement and a work of art. But be warned: while these jumbo rings dazzle on the red carpet, only some may be suitable for everyday wear.

One factor in determining a gem’s durability is its hardness or resistance to scratching. (There are other durability factors like toughness or resistance to breaking; and stability –  how a gem reacts to the effects of heat, light or chemicals. We’ll cover these in future posts.) Gemologists use the Mohs scale to describe the relative hardness of a stone. The scale runs from 1 to 10 and the higher the number, the harder the mineral.

We spotted some spectacular cocktail rings on the fingers of celebs at last fall’s Emmy Awards, and couldn’t resist rating them on the Mohs scale.

Diamonds rank a perfect 10 on the Mohs scale, and appeared on Emmy-winner Claire Danes from Showtime’s Homeland. She sparkled with a Neil Lane five carat elongated emerald-cut flawless diamond ring. Zosia Mamet from the HBO series Girls chose a black and brown diamond globe ring by Demarco. Uniquely strong,diamonds are the perfect accessory from the carpool to the catwalk.

Five carat elongated emerald-cut flawless diamond ring. Courtesy Neil Lane.

Beautiful and elegant black and brown diamond globe ring. Courtesy of Demarco.

Both Neil Lane ruby rings on The Big Bang Theory’s Kaley Cuoco rate a 9. Their vibrant red color is highly prized and in demand. Provided they are not heavily included, these romantic gems are quite durable for wearing daily.

Vibrant red rubies are highly prized and in demand. Courtesy of Neil Lane.

A pink topaz ring by Fred Leighton gleaming on Girls actress Allison Wiliams receives an 8.

Emeralds, like this 40 carat Lorraine Schwartz showstopper worn by Modern Family’s Sofia Vergara, rank between 7.5 and 8. Rings set with emeralds or topaz are perfect for a special occasion or a formal event. Care should be taken because they can chip, and high heat or chemicals could cause damage.

40 carat emerald Lorraine Schwartz ring worn by Modern Family’s Sofia Vergara.

Jorge Adeler “Rock Candy” ring with Citrine.

New Girl star Zooey Deschanel impressed with an ice blue tourmaline cocktail ring by Chanel. Its dazzling color range unmatched, tourmaline’s hardness is rated 7 to 7.5. Right alongside with a hardness of 7 is the citrine, worn by Taylor Schilling from the new Netflix series Orange is the New Black. Her “Rock Candy” ring by Jorge Adeler glistened a warm yellow. Both tourmaline and citrine could be damaged by chemicals, or prolonged exposure to sun or heat.

Zooey Deschanel wearning with an ice blue tourmaline cocktail ring by Chanel.

It’s best to consult a credentialed jeweler on the proper care for your valuable gems, however most stones can withstand mild cleaning with warm, soapy water. Learn more information on the Mohs scale and how other gems rank before your next purchase.

The post Ranking the Rings – How to Choose a Valentine’s Day Gift that Will Withstand the Test of Time appeared first on GIA 4Cs Blog.

Diamonds are known for being one of the hardest substances on earth. A diamond is so hard it ranks as a 10 on the Mohs scale–the highest level of hardness. But what is the Mohs scale?

The Mohs scale (pronounced MOZE) rates the hardness of gems and minerals. The hardness of a stone indicates the stone’s resistance to scratching or how the surface of the gem will respond to contact with a sharp point. This differs from a gem’s toughness, which is defined by how well a gem can survive an impact or resist breaking, chipping or cracking.

Introduced in 1822, the scale originated when Friedrich Mohs chose ten minerals and assigned numbers to them based on the relative ease or difficulty with which one can be scratched by another. His studies resulted in the scale below, which is still used today.

When looking at the Mohs scale, it is important to remember that the difference in hardness between minerals, or the hardness numbers, is not actually equal, even though the minerals look to be equally spaced. The diamond is only one number away from the Corundum mineral (which includes rubies and sapphires), however it is many times harder then the gems in the Corundum family.

The Mohs scale helps to identify what makes a gem durable. The more durable a gem is, the more suitable it is for use in frequently worn jewelry.

The post Mohs Scale – Gem and Mineral Hardness appeared first on GIA 4Cs Blog.