Wire-Sculpture Blog Jewelry Making Tips, News & Videos...Join the conversation

Gemstones & Beads Archives

by Narlene Allen, Wire-Sculpture.com

Today's Gem Profile is...

Jewelry Measurement Conversions and Charts

Resource Center

This week were going to focus on a very rare and beautiful gemstone called Zultanite, however Layna, our Gem Profile contributor, was out ill. Since we don’t want to miss the wonderful information that she has to share, we are going to postpone that topic and come back to it in a couple of weeks! I can’t wait to hear what she’s discovered about it and we wish her a speedy recovery!

So, in the place of Zultanite, we are going to discuss the conversions of measurement for gemstones, beads, wire gauge and jump rings.

In the jewelry world, millimeters, as we all know, is a common form of measurement. However, if you’re like me, you have to think about the conversion. Today, I thought we’d take a quick look at how to figure it all out.

If you haven’t been to our Resource Center lately, there is a great article which covers a lot of this information as well. Today though,  I”m only going to touch on a small portion because I want you to all go on a little treasure hunt and see what you can find!


How to start:

Cabochons and beads are commonly measured in millimeters (mm), while many people in the United States are more familiar with inches (in). Here are some easy ways to figure out what size cabochon or bead to work with!.

  • To convert inches to mm, multiply inches by 25.4
  • To convert mm to inches, divide millimeters by 25.4


In most cabochon measurements, the height comes first, then the width (which may seem backwards).

Here are some common cabochon sizes, in millimeters and inches.

8 x 6mm Cab

8 x 6mm Cab

0.3″ x 0.25″ Cab

14 x 10mm Cab

14 x 10mm

0.6″ x 0.4″

18 x 13mm Cab

18 x 13mm

0.7″ x 0.5″

25 x 18mm Cab

25 x 18mm

1″ x 0.7″

30 x 22mm Cab

30 x 22mm

1.2″ x 0.7″

40 x 30mm Cab

40 x 30mm

1.6″ x 1.2″

  • Remember, there are 10 millimeters in 1 centimeter, so a 40 x 30mm cab can also be measured as 4 x 3 centimeters. Most rulers in the U.S. have one side for inches, and one side for centimeters.
  • For comparison, a U.S. Quarter is 24.26mm in diameter (across); a quarter is nearly the same size as a 25mm round cabochon.


U.S. Quarter


25mm Round Cab

25mm Round



A U.S. Penny is 19mm in diameter, or 3/4″ across. Here’s a penny compared to an 18 x 13mm cab:


U.S. Penny (19mm)

18 x 13mm Cab

18 x 13mm


Do you want to know the number of beads in a strand? If you know the length of the strand and the size of the beads, you can estimate the number of beads in any strand. Note: this method may not work on beads of different sizes on the same strand.

  1. Take the strand measurement and convert it to millimeters. On Wire-Sculpture, most of our strands are 16″ long, or 406.4mm
  2. Divide the strand measurement by the size of the bead.  For example, we have a 6mm round bead.6mm Bead406.4 ÷ 6 = 67.7

There are about 67 beads in a strand of 16″ 6mm beads. Each strand may vary slightly by a few beads in either direction.

What did you learn?

If you’d like to read more about Wire Gauges and Jump Rings – you can continue reading this article in our Resource Center! It’s great information for anyone from the beginner to the advanced wire artist.

Next week, we have some very exciting news – do you love new beads? I do! We will be hearing all about a NEW line of Large Hole Round Beads that are now available on Wire-Sculpture. You won’t want to miss next weeks profile!

Do you have any beautiful jewelry you’d like to share with us? Send us pictures at tips@wire-sculpture.com and they could be featured!


Gem Profile by Narlene Allen

Click to Receive Daily Tips by Email

by Layna Palmer, Wire-Sculpture.com

Today's Gem Profile is...

Pearls – Saltwater and Freshwater

Creation, Cultivation and Care

Shop Pearl beads

Just recently we talked about Mother of Pearl and the different types of mollusks or invertebrates we use for Mother of Pearl.  Last year about this time Rose also wrote an article on the historical uses and value of Pearls. This week, we’ll go a little deeper into the world of pearls and talk more about their creation, cultivation and care.

What are Pearls?

In nature, the creation of a pearl is very rare event. It is caused by a foreign object getting into the body of the mussel or oyster causing the animal to coat the object with nacre which creates a pearl. Man has taken this process to the next level by cultivating pearls within the oysters on farms. These farms are located in saltwater bays where the oysters live on ropes which are hung below floating docks. The temperature of the water is monitored constantly and the oysters are raised and lowered to keep them at the correct temperature at all times. They are also fed an optimum mixture of algae and nutrients to keep them healthy.  Once a year, they are pulled from the water, their shells cleaned and treated with anti-fungal solution and put back in the water to finish growing.

Pearl being extracted from an oyster

A pearl being extracted from an Akoya pearl oyster.


Millions of oysters are nucleated every year with surgical-like precision, but only a small percentage actually create a pearl with many succumbing to disease or environmental problems like red tide, or too much freshwater being trapped in the bays.

It takes between 10 – 18 months to develop a pearl, the longer the oyster is left in the water, the larger the pearl becomes.  Each year only about 20% of the oysters actually create pearls suitable for market.  Today there are nearly 2000 oyster farms in Japan creating these beautiful gems using the method developed over 100 years ago.

Pearl Nuclei from Japan.

Pearl Nuclei from Toba Pearl Island, Japan

Saltwater Pearls:

South Seas Pearls are another type of saltwater pearls and are created in the white-lipped Pinctada maxima oyster. These pearls grow over a 2-3 year period and are exceptionally beautiful and rare.  The Pinctada maxima  is a wild oyster that is collected by pearl divers in water ranging from 10 – 80 meters deep.  Some divers, like those in the Philippines, don’t use any equipment opting to “free dive” for the mature oysters.  Once the healthy oysters are found, they are isolated in bays, nucleated and then placed at the bottom of the bay to grow.  After several months, the Pinctada maxima  is x-rayed to make sure the nucleus has not been rejected.  If the nucleus is still within the shell, the oyster is then placed back in the bay for 2 -3 years while the pearl forms.  Once a Pinctada maxima has developed a pearl, a farmer will carefully remove it and insert another nuclei. Healthy Pinctada maxima can be nucleated up to 4 times over its lifespan.

Pinctada maxima

Pinctada maxima

Another type of pearl is the Tahitian pearl which comes from the black lipped Pinctada margaritifera.  These are large oysters, almost twice the size of those used in Japan, and produce dark-colored pearls, often known as “black pearls” with an almost metallic luster.  These oysters are raised on farms from youth through maturity and then are cultured in the same manner as South Seas pearls.

Ring of Tahitian Pearl

Ring of Tahitian Pearl

Black Pearl

A black pearl and a shell of the black-lipped pearl oyster. The iridescent colors originate from nacre layers.

Freshwater Pearls:

Freshwater pearls are cultivated in much the same way as salt water pearls only using freshwater mussels instead of oysters.  Many archeological sites throughout the Mississippi River basin and the Eastern United States have yielded evidence that the native inhabitants valued pearls for adornment and even trade.

There is a record of the explorer Hernando Desoto in the 1540’s describing the Native Americans as wearing pearls “as big as filberts.” The “queen pearl” was discovered in New Jersey in 1857 and is a large pink, perfectly round pearl from a freshwater mussel. This pearl was eventually sold to the Empress of France.  Quite the reputation for a lowly little river mussel!  Over the next several decades, freshwater pearls were harvested and sold, nearly decimating the population of mussels in the rivers and lakes of North America.

Freshwater pearl bracelet

A lovely bracelet made by Robin Pacey with freshwater potato pearls with tiny peridot coin beads. Photo courtesy of Robin Pacey.

The best of  both worlds:

Much of the production of freshwater pearls was originally in the United States and Scotland, but when Kokichi Mikimoto began experimenting on the nucleation process, the production quickly moved to Japan and Lake Biwa. Through decades of trial and error, Mikimoto discovered that the best material for the nucleation of saltwater pearls is a piece of freshwater mussel shell and the best freshwater mussels come from North America.

Today, the production of freshwater pearls and shells in North America is undertaken by over 30 farms in various states, the first of which was the Latendresse farm in Tennessee during the 1960’s.  Now these farms not only produce American freshwater pearls, but shells for nucleation of saltwater oysters.  So literally, the beautiful salt water pearl you are wearing from the South Seas or Asia has a bit of North America inside it.

Wire wrapped necklace with freshwater pearls.

Wire wrapped necklace by Ruth Soucek with freshwater pearls. Photo courtesy of Ruth Soucek.

Handle with care:

Pearls are not only beautiful, but delicate as well.  Our skin contains oil and acids that can degrade a pearl and change not only its luster, but its shape over time.  When taking off your pearls, wipe them with a soft cloth to remove the oil and dirt from your skin. Never wear your pearls when exercising and always store them in a pouch or jewelry box, don’t hang them to store.  If you need to wash your pearls, only do so with a mild soap, not detergent, and use a soft cloth to dry them, don’t wear until the thread is completely dry.  NEVER place pearls in any type of ammonia or vinegar solution, ultrasonic or steam cleaners, or use any type of abrasives like a toothbrush to clean them.  Remove your pearls to apply makeup, hairspray or perfume as the acids can degrade and ruin your pearls. If you wear your pearls often, it’s a good idea to have them restrung every year or so.

Tying it all together!

Pearls, we learned from Rose, have been valued throughout history for their beauty and rarity. Cleopatra was said to have won a bet with Mark Antony by dissolving a pearl in wine and drinking it; proving that she could consume the wealth of an entire nation in one meal.  Pearls have been found in ancient burial sites and were even worn into battle by knights who thought the gems would provide protection.  Pearls were also a large part of the expansion into the America’s by the European’s whose lust for the beautiful gem nearly caused the extinction of the American saltwater pearl oyster.

For nearly 200 years, pearls were available only to those who were royalty, wealthy or famous. Pearls were so valuable that in 1916 when Jacques Cartier opened his store in New York City, the property was purchased with two strands of pearls.

Pearl strands

Colorful strands of pearl beads available at Wire-sculpture.com

Today, pearls are accessible to more people of diverse economic backgrounds due in large part to the cultivation of pearl oysters.

Next week, we hear about the very beautiful and quite rare Zultanite!  It’s color changing properties are amazing!

Have you made jewelry with Zultanite that you’d like to share with us? Send us pictures at tips@wire-sculpture.com and they could be featured!

Resources & Recommended Reading


Gem Profile by Layna Palmer

Click to Receive Daily Tips by Email

Gem Profile July 5: Glass, Crystal and Quartz.

by Layna Palmer, Wire-Sculpture.com

Today's Gem Profile is...

Glass, Quartz & Crystal

Shop Quartz and Crystal

Happy Fourth of July! Since it’s a holiday weekend, and we have been busy watching parades, fireworks, wearing red, white and blue and singing patriotic songs, I decided to focus a bit on the colors of our flag and how they fit into jewelry.

From the book “Our Flag” published in 1989 by the House of Representatives:

On July 4, 1776, the Continental Congress passed a resolution authorizing a committee to devise a seal for the United States of America. This mission, designed to reflect the Founding Fathers’ beliefs, values, and sovereignty of the new Nation, did not become a reality until June 20, 1782. In heraldic devices, such as seals, each element has a specific meaning. Even colors have specific meanings. The colors red, white, and blue did not have meanings for The Stars and Stripes when it was adopted in 1777. However, the colors in the Great Seal did have specific meanings. Charles Thompson, Secretary of the Continental Congress, reporting to Congress on the Seal, stated:

“The colors of the pales (the vertical stripes) are those used in the flag of the United States of America; White signifies purity and innocence, Red; hardiness & valor, Blue; the color of the Chief (the broad band above the stripes) signifies vigilance, perseverance & justice.

Red, whtie and blue flag earrings.

Red, white and blue flag earrings created by Brenda Sigafoos.

Also this from a book about the flag published in 1977 by the House of Representatives:

The star is a symbol of the heavens and the divine goal to which man has aspired from time immemorial; the stripe is symbolic of the rays of light emanating from the sun.

Let’s talk Glass, Quartz and Crystal:

A couple of years ago, Dale Armstrong did a series of gem profiles about quartz.  In her profiles she touched on several different types of glass that have been labeled as quartz.  Technically they were since both quartz and glass have the same base of silicon dioxide (SiO2), however, the main difference between glass, quartz and crystal is the arrangement of the atoms and the basic molecular structure of the material.

  • Glass is considered an amorphous solid; it doesn’t have a crystalline structure and is made primarily of silicon, potash, lime and soda.
  • Quartz crystals are pure silicon dioxide and found within the earth.
  • Crystal is made with silicon, sodium and lead, making the atoms in the glass line up and form crystals which allow it to be carved and faceted easier than glass.

In jewelry making, we use all three materials; glass, quartz and crystals. Today I thought it would be nice to touch on all three.

What is Glass?

Glass beads are made from a thin reed, or cane, that is cut, drilled and polished. The most familiar type of glass in jewelry making would probably be the seed bead and fire-polished Czech beads. Czech glass beads are faceted and then put in a furnace to “polish” the rough edges with heat. They have to be careful during the process or the beads will melt. These types of beads are amorphous and are not as bright and don’t have the refraction properties of crystal.

What is Quartz?

Quartz, the beautiful and natural stone, comes in a variety of colors from rose to smoky and has been valued throughout the centuries for jewelry and other gemstones.  Some of the most familiar quartz gems are Amethyst, Citrine, Smoky and Rose quartz.  The color of the quartz depends on the end ions when the Silicon Dioxide was forming into crystals. For example; the iron that creates the beautiful purple in amethyst.

Rose Quartz Necklace

Rose Quartz Necklace. Created by Peggy L. Marzano.

What is Crystal?

Crystal is similar to quartz in that it has a crystalline structure and is also made of silicon dioxide.  The only difference is that it is man-made just like a Cubic Zirconium, and is the same chemical composition as diamonds.  Crystal is glass made with silicon, sodium and lead.  The lead makes the atoms in the glass align turning it from an amorphous solid into a crystal.  Anciently, trace amounts of lead were used to color glass, but not enough of a concentration was used to turn the glass to crystal. This process wouldn’t be developed until 1676 when an Englishman by the name of George Ravenscroft added lead oxide in a higher concentration making the glass more clear, more durable and able to be carved and faceted into glasses and beads.

tibetan crystal quartz in Dale's collection

This unusual specimen comes from Tibet. Notice not only the exotic crystal scepter growth, but also the clay inclusions within the bottom crystal.

About Crystal:

In 1891 Daniel Swarovski invented a machine to cut and facet crystal beads exploiting the refractive and reflective nature of the crystal to give us Swarovski Crystal.   Swarovski Crystal contains up to 32% lead dioxide. The addition of lead to glass not only turns it into a crystal, but also lowers the melting point and makes it softer and easier to carve and facet. It’s the lead that gives the crystal the clarity and sparkle we love.

Swarovski crystals

Swarovski crystals

Tying it all together!

So at this time of year when we are wearing the colors of our nation; Red, White and Blue, remember that they symbolize the values of a people, and they’re a lot of fun too!

Next week, we will discuss Pearls – freshwater, saltwater, natural and cultured!

Have you made jewelry with any type of pearls before? Send us pictures at tips@wire-sculpture.com and they could be featured!

Resources & Recommended Reading


Gem Profile by Layna Palmer

Click to Receive Daily Tips by Email

Gem Profile June 28: Jet

by Layna Palmer, Wire-Sculpture.com

Today's Gem Profile is...


Shop Jet Beads

This week I think we’ll start with a road trip!  We’ll be “leaving on a jet plane” destined for Whitby England, which is on the Yorkshire Coast. There we’ll be visiting the W. Hamond Boutique which has been in business since the 1860’s selling a stone that Shakespeare described in Henry VI as “Coal-black as Jet.”

W. Hammond Boutique

W Hamond Whitby Jewelery Boutique. Photo courtesy of W. Hamond Whitney Boutique

Whitby is a typical English fishing town complete with cobbled streets, quaint shops and a beautiful Abby that overlooks the village. If you walk along the beach, you may notice some spots in the cliffs where holes have been dug out, filled in, or eroded away. There are also portions of the cliffs where large sections or lines of black rock are noticeable against the grey of the shale. These sections are called a “jet line” and are where our gemstone story really begins.

Shale Jet Line

A distinctive shale or ‘Jet line’ on the cliff face. Photo courtesy of W. Hamond.

What is Jet?

Millions of years ago, during the Jurassic period, carboniferous forests grew in this part of England.  One of the most prominent trees was one similar to our modern day Araucaria, or Monkey Puzzle tree. These large trees would either die and get washed into the sea, or be carried to the sea during violent storms where they would become waterlogged and sink to the bottom of the ocean not far from shore.  As the millennia passed, silt and sand encased these logs, compressing them into what is now known as Jet.

Carved Jet

Carved Jet Pendant

Jet is a form of Lignite, which is a variety of coal.  Jet, though considered lignite, is more dense than common lignite, and though soft (2.5-4), can take a nice polish. Jet is found throughout the world in various areas, but the Jet from the area of Whitby, England specifically, is a true black jet with few inclusions, and can be easily worked on a lathe or in carvings.

About Jet:

Jet has been known throughout the European Region for centuries with early specimens being found in Germany dating around 10,000 BC, and Spain from around 17,000 BC.  The Romans were very familiar with Jet, calling it Gagat, and made beads, buttons and carvings that have been found in and around Whitby. Jet was also used by Bronze Age people for carvings, beads, bracelets, rings and amulets.  Anciently Jet was thought to ward off evil spirits and protect its wearer from harm.  The monks in the Abbey also used Jet to carve rosaries and other ornamental items. In more recent times, even Shakespeare was familiar with Jet and referenced it in several of his plays and sonnets.

Jet gained popularity during the Victorian Age when it went on display at the 1851 Great Exhibition in London where it came to the attention of several members of royalty in Bavaria and France. It wasn’t until Queen Victoria took to wearing Jet as part of her mourning jewelry when her husband Prince Albert passed away, that Jet really became popular.

Antique Cameo Pendant

Victorian Antique Whitby Jet teardrop shape pendant with a faceted edge and a cameo center piece. Photo courtesy of W. Hamond. The Original Whitby Jet Shop

Jet, though dense, is soft and light therefore it can be carved in intricate patterns without losing the integrity of the stone and takes on a beautiful sheen when polished with rouge.

Tying it all together!

Now that I have you interested in the beauty of Jet, let’s go back to the W. Hamond shop and museum.  Here you can tour a Victorian Jet workshop that was found in a boarded up building in town, speak with the workmen and even purchase some beautiful specimens of Jet either in rough or in settings. Though the government has never allowed actual excavation or mining of Jet, Victorian Age workmen would find the Jet, excavate it from the cliffs and then fill in the rock afterwards. They would even pick up loose pieces from the beach.

A “little” piece of history:

W. Hamond is the proud owner of the largest Jet gemstone known; at 21ft in length and 180 million years old, it is truly a marvel of nature and a piece of history.

Largest Jet

W.  Hamond employees recreate a bygone era as they hold part of the World’s largest Whitby Jet gemstone. Photo courtesy of W. Hamond.

*A special thanks this week goes to the W. Hamond shop for the information provided to Rose at Tucson this past year, and to Chris Sellors specifically.  For more information on Whitby Jet, please follow this link to the W. Hamond site where you can not only take a look at their products, but also the history of Jet and some wonderful pictures of Jet from excavation through the finishing process.

Next week, we will discuss crystal – lead vs. mineral! We will be talking about the “Colors of Liberty.”

Have you made jewelry with any type of Crystal before? Send us pictures at tips@wire-sculpture.com and they could be featured!

Resources & Recommended Reading


Gem Profile by Layna Palmer

Click to Receive Daily Tips by Email

Gem Profile June 21: Rutilated Quartz

by Layna Palmer, Wire-Sculpture.com

Today's Gem Profile is...

Rutilated Quartz

Shop Rutilated Quartz Beads

This week I thought we’d try something a bit different. We’re going to take a look at two different types of minerals with different chemical compositions, hardness and even form at different temperatures under different types of environments; yet they are often found together.  When I say together, I mean literally; one growing within the other. So how does this happen?  Science hasn’t quite figured that one out yet, but they’re working on it.  It reminds me of the question that came up as I was changing a light bulb the other day. I pulled the bulb out of my lamp only to find that there were three little bugs in it.  I have no idea how those gnats got in my light bulb, but there they are!

What is Rutile?

The first mineral we’re looking at is Rutile.  From the profile last week, we learned the rutile creates chatoyancy within a stone and is responsible for the stars, or asterism, in stones as well. Rutile is composed of titanium dioxide which is a main component of refractory ceramics, titanium metal, and the bright white pigment used in plastics and other items that are  bright white in color.  Interestingly enough, it is also used in sunscreen due to its ability to absorb ultraviolet (UV) light.  So, rutile has a base of titanium, but when associated with other minerals, can be different colors and create different effects within a stone. We will talk about golden rutile a little later in this post.

Synthetic rutile has been around since the late 1940’s and has even been used as a diamond substitute called “Titania,” but at only 6 on the Mohs scale, it’s not as durable as a diamond and is not used much now in jewelry.  Rutile, whether natural or synthetic is still a 6 on the Mohs scale and is found in various areas of the world generally associated with volcanic regions and quartz.  Though rutile forms at lower temperatures and pressures than quartz, it’s also found inside quartz crystal. When the rutile grows within quartz, it takes on the name; rutilated quartz.

Rectangular clear quartz ring

Adrien De Ruyck created this lovely ring with a rectangular clear quartz with reddish brown and black rutiles.

About Quartz:

Quartz, one of the most common minerals on earth, is found on every continent and makes up 12% of the Earth’s crust; it’s a pretty common mineral.  Quartz is created at high temperatures and pressure with varying inclusions giving us different types of quartz from clear to rose and smoky.  One of the most beautiful types of included quartz is rutilated quartz.  Rutilated quartz can be found in Australia, Brazil, Kazakhstan, Madagascar, Norway, Pakistan and the United States.

Golden rutilated quartz was first found in Brazil in the in the Serra da Mangabeira mountain range in the 1940’s where miners were originally picking up pieces of clear quartz for optical uses. The included rutilated quartz was discarded, not being of much value in optical applications, and eventually, some of the material made its way to Bahia, Salvador where the gem dealers saw, well…a gem!

Golden Rutilated Quartz

A beautiful piece of golden rutilated quartz.

The rutilated quartz from this region has beautiful golden threads throughout the stone.  This golden rutile is associated with hematite and grows in impressive thick strands within the quartz. Because golden rutile is also composed of titanium dioxide, it has high concentrations of hematite, while the rutile responsible for asterism is mostly asbestos. This type of rutile rarely forms stars within the stone, but instead gives us a beautiful long thin needles of color due to the orientation along the axis while the rutile is developing.  Since quartz has a hardness of 7 and rutile is a 6, it can be difficult to cut and polish a rutilated stone without creating pits and cracks in the quartz.

Golden Rutilated Quartz Cabachon

Golden Rutilated Quartz Cab. Photo provided courtesy of Adrien De Ruyck

Tying it all together!

Now, getting back to the gnats in the light bulb; just how does rutile form within quartz?  When quartz forms, it is at extremely high temperatures – pressures usually associated with volcanic activity.  When lava degases it created bubbles or vugs and pegmatites which form large crystals at the end-stage of cooling.  One of the theories is that quartz permeates a vug and then the rutile precipitates and grows within the stone as it cools.  The other one is that as the quartz pegmatite is cooling, it develops microscopic cracks which allow the rutile to grow.  Either way, the strands of rutile develop within the quartz giving us a beautiful color show of long thin needles within a clear stone, which is why rutilated quartz goes by the names Bahia Gold, Venus hairstone, and cupid’s darts.

Lemon Quartz earrings

Lemon Quartz wrapped in gold filled and rose gold filled wire with Swarovski crystals and pearls. Created and photographed by Sherry Dusza

Next week, we’ll “jet” off to learn a little about lignite!

Have you made jewelry with any type of Jet before? Send us pictures at tips@wire-sculpture.com and they could be featured!

Resources & Recommended Reading

A special thanks to Brian Charles Cook:


Gem Profile by Layna Palmer

Click to Receive Daily Tips by Email

 Page 5 of 48  « First  ... « 3  4  5  6  7 » ...  Last »