History of Glass - Venetian Bead Shop Blog

Calcedonia Glass – Technique from the 15th Century, Lost and ReFound!

Calcedonia Glass Sculptures – San Marco Square Glass Shop

Calcedonia (Chalcedony) is a glass made with silver and other elements (glass is above all a chemical reaction which takes place in heat), developed in Murano during the mid fifteenth century. Angelo Barovier is attributed with developing this polychrome glass around 1460 (the 15th Century).The Barovier name has been synonymous with Murano Glass since the furnaces were moved to Murano from Venice. This famous family was granted the exclusive rights to the production of clear glass by the Venetian Repubic about 1455. The technique of this clear glass became known as crystal glass or Venetian crystal, which was a significant development in the story of glass and of the island of Murano..

The secret of the Calcedonia glass was closely guarded and entirely lost when the Venetian Republic fell. It varies widely in the colors which come out of the furnace, subject to the heat of the silver, humidity and the humor of the glass maker!

It was once again rediscovered by Lorenza Radi in 1856 but again by the 20th Century none was in production. Today we thank Loredano Rosin for bringing back this technique in the 1970s. His pieces are still on exhibit around the world and in private collections. His untimely death from a boating accident was a blow to the artistic Murano Glass community.

Fortunately, his brother Dino Rosin, carries on the family tradition and has continued to perfect this glass in large and beautiful glass sculptures. You can still find Dino Rosin sculptures available at very hefty sums on eBay and in fine galleries around the world, just search for his name. Today, there are several other well known masters who create sculptures in this unpredictable glass, including Tagliapietra.

For all of us in the Venetian Bead world, we are fortunate that there is another furnace who produces (with proper begging) canes of this unpredictable glass which we can chop and use in beads. However, this is a difficult production and we can only get small quantities made – never knowing what color will arrive.

We all dream of the blues and aquas…and sometimes we get it. The amazing, never the same, colors are produced by adding silver nitrate to the glass and the colors are affected by the humidity, the heat, and factors we don’t understand. The glass begins as salt, soda, sand and minerals days before the glass master is ready to work. The recipes for glass depend on very accurate measuring and minerals of the highest quality. Any small difference will result in color changes or in glass which does not react well in the flames when the beads are being made. It pops and cracks. The Calcedonia has a mind and life of its own, the colors can not be reproduced with any certainty. They continue to turn colors in the flames as the beads are made and even after the beads are in the annealing oven.

Making a Calcedonia Sculpture Murano Italy

Here are the colors of our latest batch, with added sparkle from Aventurina.

We must enjoy each batch of beads for what they are: unique little jewels!

Marvin Lipofsky – US Glass Movement Pioneer

Marvin Lipofsky, remains a legend in the US glass movement. His contributions are numerous. He was large burly glass artist known for his irascible temperament, an artist who pushed the theories on glass (and his students) as a medium influenced by his original studies in clay.

The picture is part of our “selfie” a new word for Marvin that we made at the San Jose Glass Art Society Conference in June 2015. He arrived at the party at the Tech Museum with only a hand written name tag. No one dared point this out. His size and reputation preceded him – everywhere.

He was among the first students in the Harvey Littleton‘s emerging US Studio Glass Movement and with the exposure to glass, his focus changed. With his MFA in sculpture, he went on to teach at the University of California Berkeley and in 1967 founded the glass program at the California College of Arts and Crafts. And the rest, as they say, is history.

For his full resume you can visit his website

He was one of the early members of the Glass Art Society (G.A.S.) and wore many hats organizing and promoting this world wide association which today has over 2,700 members from 50 countries. He received the Lifetime in 1986 and was on hand in 2015 to see his student Mary White receive this prestigious award. Though classic, Lipofsky, he was still critiquing her work, always pushing his students.

Along the way he has studied and taught in over 50 cities around the world. This video was filmed at the Oakland Museum in California with Lipofsky in his own words.

Lipofsky’s work has been collected by many public institutions worldwide. In the United States his work can be found in the collections of the Corning Museum of Glass in Corning, New York; High Museum of Art, Atlanta, Georgia; Los Angeles County Museum of Art, Oakland Museum, Oakland, California; Metropolitan Museum of Art, New York City; Philadelphia Museum of Art and Toledo Museum of Art, Toledo, Ohio. Overseas his work is in Glasmuseet Ebeltoft in Denmark; Glasmuseum Frauenau (de) (Sammlung Wolfgang Kermer (de)), Germany; Museum Bellrive in Zürich, Switzerland;Museum Boijmans van Beuningen in Rotterdam, Holland; National Museum of Modern Art, Kyoto, Japan and Hokkaido Museum of Modern Art in Sapporo, Japan

To say that his work lives on, is an understatement.

Quantity is really how hard you work – NOT a definition of “Art”.

I have been a member of ISGB (International Society of Glass Beads) for about 15 years and GAS (Glass Art Society) equally as long. So I was a little taken back when I received a pamphlet at the GAS conference here in San Jose, CA (where I spent 3 days volunteering) called “How to Buy Glass Beads – A Shopper’s Guide to Finding Quality Art Glass Beads” which is a real “looking down the nose” at those of us who produce more than 5 beads a week.

OK, so you can see I am not making this up, I just scanned it in so everyone can read – (hopefully not our bead makers who would be terribly offended!)

And inside it continues…

The prices of the factory-made beads are often “too good to be true”. We work very hard to keep prices down and deal with not only fluctuations in the Euro but also in precious metals pricing.
Another sign of factory-made beads is quantity – the fact that our bead makers show up every day and make beads is a penalty?
Is the work “professionally” displayed (This means 5 beads of in a plate of rice?)
Quality and Techniques used for centuries in Murano are not “real” EXCUSE ME? Where do you think ISGB beadmakers learned?
Ask the seller to tell you the name of who made bead: Yes, really I am going to reveal my beadmakers whom I have cultivated, spend millions – YES, and 20 years of my life to develop.

PLEASE, the Venetians and Muranese have been doing this since the 800s and before. Recent discoveries in Altino digs have uncovered murrine (millefiori) from the 1st Century AD. Altino was destroyed in 452 AD by Attila forcing its people into the islands we now know as Venice.

American “artists” came along only few years ago. The fact that our wonderful bead makers support themselves, raise families, send their children to college, buy homes (and YES they can make quantity) only adds to their status as artists. Most of the beads these so called “ISGB artist” make have origins in Venetian Beads.

Quantity is really just a matter of how hard you work – NOT a definition of “Art”.

For example the Chevron Bead in the brochure that you see above – no artistic work there, just copycat of Venetian and from even earlier bead makers.The development is absolutely Murano in the late 1400s as documented in The History of Beads by Lois Sherr Dublin, the “bible” of beads, ISBN 0-8109-2617-2. I recommend this book to anyone who is interested in the history of beads around the world.

Among my bead makers, I count

One who owned his own Murano Glass furnace – until his wife making beads became so successful he closed the furnace and now works for her.
A maestro who worked at Venini (Murano Glass Furnace) – have you seen their pieces? I dare you to say he is not an artist!
One who began as an apprentice in a furnace at 12 years old, and has raised 2 daughters making beads in his home.
One who began as an apprentice at 13 in the Seguso Murano Glass Furnace under the famed Archimede Seguso, who was a truly demanding Maestro.
One who is a 3rd generation Venetian bead maker – bead cards from his family are in museums around the world.
One who learned from her mother, who worked in one of those “factories” and is considered the Queen of the Fiorato bead in Venice and Murano.
A maestro in a Murano Glass furnace who invented machines so he could produce blown beads easier (and in quantity) :>)
And many more! And I count them all my friends and respect their work!

They will work day and night, weekends to produce the beads we need.

I find it very interesting that any glassblower, Chihuly included, will acknowledge immediately that Murano is the cradle of glass blowing and respects their Maestri. Yet ISGB somehow believes they invented bead making.

Might I remind them that the Doge of Venice gave the right to make beads to the crafts people Venice in a decree in 1291 when the furnaces moved to Murano? And that the “union” of beadmakers in Venice and Murano dates back to 1308 when the State Inquisition organized the beadmakers into a Guild “Arte de’Margariteri” while the ISGB is a mere baby having been formed in 1993.

Incidentally that is the same year we began importing VenetianBeadShop.com began importing beads from Venice and Murano.