Spinel Rough Cut Gemstones & Finished Jewelry

Gemstones You Need to Have in Your Jewelry Collection

Henne Jewelers is known for its impeccable customer service, legacy and place in Pittsburgh history, and of course for having the finest selection of jewelry for every style and budget.

Choosing Henne as your jeweler comes with additional benefits as well! In addition to having 3 in-house jewelers, 2 watchmakers, and Henne Exclusive designers, Henne is proud to also have 3 gemologists. We carry an extensive array of natural, ethically sourced gemstones that you won’t find at many chain jewelry stores.

Bert Esterhuysen, one of our gemologists who originally hails from South Africa, has spent his life studying gemstones. He works with the most reputable suppliers and mines across the world to provide Henne with stones that are of the highest quality. For our customers, that means you can shop jewelry featuring precious to exotic gemstones – some very common and others incredibly rare.

So what are Bert’s favorite gemstones and why? We asked him, and he answered. Here they are, in no particular order. Click on a gemstone to learn more!


It gave us the science of gemology (and it's really bright and pretty). A lot of famous rubies and sapphires are actually spinel, so Bert likes to give credit where it’s due, especially because it's become regarded as history's most underappreciated gem. The most famous spinel is the Black Prince's 'Ruby' in the British Imperial Crown.

Other fun facts: Spinel is one of three birthstones for the month of August, and it's symbolic of the 22nd wedding anniversary. This special gem can be found in a variety of rich colors - red, blue, orange, pink, and violet, just to name a few. Rose-red spinel is still known as “balas ruby”, which on some level hints to its illustrious history as an imposter.

Pictured: Stones from Bert's personal collection, all from Burma. The left ring is SKU 85980 and the right ring is SKU M87775.


Some may think it’s boring, but Bert likes black, and it was the first gemstone he ever received in a piece of jewelry. It’s tough and relatively durable.

Onyx is a type of chalcedony. This opaque black gemstone looks great faceted or as a cabochon, and is versatile in that it looks great with various metal types. It's also affordable and works with a variety of jewelry styles, from vintage to contemporary designs.

Star Sapphire

Bert loves the fact that something on the inside can show on the outside. It's science, but it looks like magic! On some level this makes him think of Arthur C. Clarke and his third law: "Any sufficiently advanced technology is indistinguishable from magic.”

The star sapphire gets its name from the six-ray pattern that appears across a cabochon-cut sapphire. The 'star' is actually light reflecting off of the sapphire's tiny needle-like rutile inclusions. It's relatively rare, with the highest quality star sapphires showing distinct rays that are visible from a foot or two away. It should also have elegant movement, meaning that as the gemstone tilts, the star should appear to move as well across the surface.

Photo from the Gemological Institute of America.


Bert's favorite color is green, and he likes stories, so noble serpentine, or gem-quality serpentine is a perfect fit.

The serpentines consist of three minerals (chrysotile, lizardite and antigorite) that for the most part are used to imitate other gemstones like jade or hydrogrossular garnet. This centuries' old imitation game has resulted in misnomers in the trade where people call it serpentine-jade or new-jade.

Finding these pieces in finished jewelry is a fun and rewarding experience. It's not found as often in jewelry, but Bertus Design may add a ring, pendant, or bead bracelet at any time! Hues range from very light yellowish-green to earthy green, making it a lovely color for spring or summer.

Fun fact: The unofficial Pennsylvania gemstone is Williamsite – a chrome-green or apple green antigorite noble serpentine. Between 1828 and 1860, the chrome mines in the State Line District of Lancaster County were the only source of green pigment for the manufacture of paint in the Western United States, leaving the question of how many gem grade pieces ended up becoming paint.

Left Photo: precious serpentine (the ring in the image is bowenite, SKU #M90286), and the big piece of rough is chrysotile. Both stones were collected by Bert -- the bowenite from South Africa and the chrysotile from Swaziland (formerly known as Eswatini).


Taaffeite was the first gemstone to be identified as a cut stone (not as a crystal or rough pebble in its natural environment). It's actually very rare and is commonly mistaken for spinel.

The stone was named after the man who 'discovered' the gemstone in 1945, gemologist Count Edward Charles Richard Taaffe of Dublin, Ireland.

As the story goes, he was sifting through a collection of gemstones and saw a mauve-colored gemstone that looked like spinel at first. But upon looking closer, he noticed some differences -- most notably that the stone was doubly refractive (spinel is singly refractive). He sent it away for more testing, and it was confirmed as a newly discovered gemstone.

Taaffeite comes in various colors ranging from pink to purple. It is only sourced from a few places in the world such as Sri Lanka, southern Tanzania and Myanmar.

Photos courtesy of the Gemological Institute of America and National Jeweler.


If you're looking for a 'modern' stone, sugilite is a great choice. It has an amazingly rich and royal color ranging from vibrant pink to deep purple, thanks to small amounts of manganese.

Sugilite is a rare find that doesn't sparkle, but still exudes luxury. The stone was first described in 1944 by the Japanese petrologist Ken-ichi Sugi, but it was only found in larger quantities in 1979. For that reason, it isn't well-known and hasn't been marketed extensively.


There is nothing that beats the "play of color" you see when looking at a very fine opal. It’s extraordinary. No two opals are alike, and it really feels like you're looking into a galaxy in the palm of your hand. Pictures, and even video, can’t convey its exquisite beauty of kaleidoscopic colors. Varieties include white opal, black opal, fire opal (may not show play of color), boulder opal, and crystal or water opal -- each stunningly beautiful in its own right.

Discovery of opal in Ethiopia in the early 2000s has opened up ownership of fine pieces to the general public, so you don't have to spend a fortune to own something pretty. Opal is the birthstone for October and is better for occasional wear, due to it being not as hard or tough as other gemstones.

Montana Sapphire

It's hard, it's durable, it's rare, and it's as “American Made” as you can get. Also, there is an absolute rainbow of color coming out of Montana, thanks to its rich mineralization.

Montana has produced more gem-quality sapphires than anywhere else in North America, earning it the name of The Treasure State. Sapphire is one of the state's official gemstones.

Paula Crevoshay designed a beautifully ornate butterfly using Montana sapphires, which is on display in the Gem Hall at the Smithsonian Institution's National Museum of Natural History.


It's beautiful and special, but because of its rarity this gemstone remains unknown to many jewelry enthusiasts; it remains a prized collector's stone.

Jeremejevite was discovered in Russia in 1883, but it wasn't discovered in large, facetable crystals until the 1970s in Namibia. This stone comes in a wide range of colors, including colorless, blue, yellowish-brown, and even violet. The light blue hues are similar to aquamarines, but have twice the amount of sparkle.

Bert grew up in South Africa and occasionally spent time on the beach in Swakopmund, Namibia. He recalls hearing someone talk about jeremejevite at a barbeque, and because of that he bought his first faceted stone more than a decade later without ever having a reference for it. Over the years he's added a few more stones when they were available.

Photo to the right: The largest faceted stone in that photo is a mere 0.80ct. You don’t buy jeremejevite for its size; you buy it for the sparkle and the story. All stones are from Namibia and are part of Bert's personal collection.


Again, Bert loves green! Nothing comes close to the richness of this copper ore. If you want green and nothing else, this is the stone for you!

Malachite is affordable, fun and interesting with its patterns, zoning and bands of various green hues. It has a low hardness, which makes it ideal for carvings and decorative pieces.

We’ve had a number of malachite jewelry pieces at Henne, ranging from unisex bead bracelets to statement pendants, including this one by Nina Pugliese.

Malachite slices show the stone's unmatched beauty found within. The color contrasts remarkably with yellow gold, and diamond accents create an air of femininity.

Bonus: A Quartzite Pebble

You can collect gemstones and jewelry for years, seeking the rarest and most valuable on the market. Bert shares that he lives it every day for Henne customers. But just like our clients, sentimental value has no limit. He says, "My 18-month-old son picked up a quartzite pebble the other day during a trip to Presque Isle, and is it any surprise that it’s now one of my favorites?"

Favorite Gemstones & Priceless Jewelry

If a stone has special meaning to you, it becomes priceless. That’s why we create so many custom rings and necklaces at Henne using family heirlooms or other sentimental gemstones. There’s nothing quite like wearing an engagement ring that contains your grandmother’s diamond, or having a ring made with a Montana sapphire you got during a trip out West with your dad.

A parting word from Bert: "The world of gemology is incredibly fascinating and wide. It’s a privilege to serve Henne customers and make this world available to them going far beyond the status quo, whether it’s the stone itself, rough or faceted, how it appears in the jewelry, or the story behind the story. I always look forward to talking with customers about gemstones, educating them, and providing them with jewelry beyond their wildest dreams."


Bert Esterhuysen at the Vioolsdrift Bowenite mine, circa 2012/2013 (taken by Estelle Esterhuysen).

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