Slag glass has a rich history that makes it extremely valuable to collectors. Atterbury & Company, Challinor Taylor & Company, and H. Northwood Glass Company are some well-known manufacturers from the United States. True slag glass is marbled and has a variety of bright colors. This byproduct can then be pulverized and used as a glass additive. Some of the most popular manufacturers were Miller, Bradley & Hubbard, Empire Lamp Manufacturing Company, Pittsburgh Lamp, Brass and Glass Company, H.E. $75.00 + $67.15 shipping. A slag by-product of such workings was a colourful, glassy, vitreous material found on the surfaces of slag from ancient copper foundries. Slag glass is named after silicate slag, a colorful material that is a byproduct of molten steel. As technology and manufacturing changed over time, new colors have been introduced to the slag design. This is one of the most common uses for slag glass, and you'll see many slag glass chandeliers and other fixtures in antique shops. Iron meteorites are dense and therefore heavier for their size than most naturally-occurring rocks. Because . [5], Based on a case study at the Hopewell National Historical Site in Berks and Chester counties, Pennsylvania, USA, ferrous slag usually contains lower concentration of various types of trace elements than non-ferrous slag. Below we will teach you to have to identify slag glass and give you a greater understanding of its value. The original slag glass is brown with creamy streaks, a similar pattern to how your cup of coffee looks when you first pour in milk or creamer. Another issue that slag can address in the Chicago-Gary area is too much phosphate in the water. Steel Slag Rock Cost. Fiberglass insulation is made from molten glass that is spun or blown into fibers. Serious antique glass collectors will be familiar with "slag glass" which became popular in the late 1800s and is still made today. Some of the earliest such uses for the by-products of slag have been found in ancient Egypt.[9]. Remember, the most common way to make slag glass was by skimming silicate material from the top of molten iron. Manufacturers experimented with different methods to achieve this malachite-like look. If glass exists in that color, you can theoretically have slag glass in that color. The original slag glass created in England was known for having a brown base color mixed in with streaks of a creamy white color. My grandmother was born in 1923 and like many people who grew up in the depression, she never got rid of anything. However, the most important application is construction. This created the marbled effect and bright variations in color that make slag glass so unique. Two vintage brown Sowerby figurines can sell for two completely different processes depending on how the marbling came out. $14.46 shipping. Episode 15, (Video) How To Identify Slag Glass by Dr. Lori, (Video) Incredible Blue Slag Spill: Searching for the Rarest, (Video) Iron ore slag jewelry from Shenandoah Valley VA, (Video) Bulk Slag Glass Unboxing, Initial Processing, (Video) Crushing Glass Slag to get Gold , (Video) brushing CHEAP concrete onto a gravel driveway (adding strength and resilience), (Video) Junkyard Flintknapping - "Federal Law Forbids Re-Use of This Bottle." Your email address will not be published. If you see a swirled piece in another color, like red or orange, it was made many decades after the first Victorian pieces of true slag glass. 3 Beds. This material takes on different colors depending on the minerals and elements that are present in the iron. Slag glass, also commonly known as Malachite glass, is pressed glass made in the same way as Milk glass, but with coloured streaks to create a marble effect. Slag glass is a term used to describe a type of colored pressed opaque glass made using the "slag" left over during the iron smelting process. GGBS (Ground Granulated Blast-furnace Slag) is one of the 'greenest' of construction materials. Lamps, lampshades, and chandeliers were very popular uses for slag glass. Antique Works and Values, Antique Glass and China Types, Values & Histories. With the first versions of slag glass being an opaque brown with cream to caramel-colored streaks, slag glass is also known by the names of brown malachite or brown marble vitro porcelain (brown marble). This leads to concrete with reduced permeability and better durability. Brand New. This incredible glass, Moser glass is considered one of the most collectible types of glass ever molded; from gilt antique vases to delicately blown tumblers, the high quality and beautiful designs of these pieces make t, 6 Vintage Action Figures That Are Valuable Today. Most manufacturers use up tp 40% to 60% recycled glass content. Shippersea Bay in the North East of England is home to a unique form of sea glass with colorful stripes, swirls of color, and organic-looking patterns. Malachite stones have wavy striping in a green-tinged milky white on top of a darker green. Its only raw material is a very specific slag that is a by-product from the blast-furnaces manufacturing iron. For example, slow cooled BF slags (or air-cooled slags) tend have more crystalline phases than quenched BF slags (ground granulated blast furnace slags) making it denser and better suited as an aggregate. Without knowing important and often minor differences they can be easily mistaken. Although the construction industry does use some slag as an aggregate, most is simply discarded. Slag is the byproduct of steel production. Rainaud, and Tiffany Studios. Eventually, it became known as slagware or slag glass. With excess phosphate in water being a significant issue in the Chicago-Gary area, this benefit from slag could be another use for the material and could decrease the need to mine new natural materials for water treatment applications. Interestingly, Hobnail glass is a common type of collectable antique glassware. Slags often have very rough exteriors, unlike any stony meteorite. Samples collected from the reservoir showed the higher concentration of cadmium (Cd) and lead (Pb) that exceeded regulatory guidelines. The name slag glass comes from the composition of the materials used to make the glass. Slag glass is a type of pressed glass that is known for its brilliant and vibrant colors. Outside of the construction industry, it might seem that uses for slag are considered limited. The older piece, the greater value it has. Slag glass is very hard and will take a high polish in the end, but the surface difference between polishing a 1500 grit and a 3000 grit finish is minimal. [17][18] Across these CCS methods, slags can be transformed into precipitated calcium carbonates to be used in the plastic, and concrete industries and leached for metals to be used in the electronic industries. Depending on the rarity of the item, slag glass is worth anywhere from $50 to $1500. The marbling should be a creamy white color that is evenly mixed into the base color. Save my name, email, and website in this browser for the next time I comment. Slag glass gets its name from slag, or the byproduct of steel production. 701 South Main Street, #103. When iron-ore is smelting during steel production, the remaining residue is a glass-like, glossy material. When iron ore is smelted in that process, the remaining residue is a glass-like, often glossy material that takes on different colors depending on the minerals and elements present in the iron. Due to the large demand for these materials, slag production has also significantly increased throughout the years despite recycling (most notably in the iron and steelmaking industries) and upcycling efforts. The marbling is sometimes compared to tortoiseshell. Sowerby also created several other color formulas including Giallo (yellow), Pomona (green), and Sorbini (blue). Your email address will not be published. By clicking Accept All Cookies, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. It is hard and more durable than even the hardest metals. This being the glass version rather than stone, it makes sense to call it how you see it. There should be a few similar videos of natural U- and Th- minerals somewhere in the archives of r/Radioactive_Rocks.. 251 g Green Slag Stone Iron Ore Glass Rock . Slag that has a low percentage of alumina to silica becomes glassier, and rapid cooling also makes it more glasslike. Slag was often used as a building material, and as railway ballast, among other things, and according to one source, also for sea walls which would explain its presence on beaches. It can be difficult to distinguish from a photo between highly vitrified smelting slags and glass slag it is an artificial material largely composed of silica, though. Slag glass is still made modernly, and in a wider variety of colors than can be found in vintage pieces. This leads to marbling in the colors of the glass. The key identifying feature of this type of glass is its similarities to the patterning found in natural marble. Another early slag glass was the purple malachite glass by Sowerby, which was sold in the United States under the name "blackberries and cream." Ruby Red LLC is compensated for referring traffic and business to these companies. Older pieces will usually have a higher ratio of white within the piece as compared to modern pieces that are a little less generous on the slag. Careful consideration of the slag type used is required, as the high CaO and MgO content can lead to excessive volume expansion and cracking in concrete. Recognizing slag glass is easy due to the distinctive coloration. These are just a few of the companies that produce authentic slag glass. Sources/Usage: Some content may have restrictions. Slag glass producers mark their products with the companys initials or the companys logo. Real slag glassware will also never just be one solid color, it will always be blended. I would like to send you pictures, but am not sure how. Was: $16.90. Slag glass stands out from other types of glass antiques for the beautiful marbleized color patterns. Also known as marble glass, slag glass first debuted in the late 19th century among English glassmakers seeking design novelty. (817) 251-1668. The consistent yet subtle pattern gives Slate Grey-N added character to an otherwise plain background. The ideal thickness of each layer is between 4 to 6 inches. Popular slag glass lampshades shapes included mushroom, dome and flower petals. The light shining through the marbled color creates a really unique effect. One item where slag glass was used often was in the creation of antique oil lamps, chandeliers and lampshades, particularly during the Art Deco and Art Nouveau periods during the late 19th and early 20th century. Work with a qualified appraiser to help you identify the manufacturer and type of slag glass antiques you have, including antique glass insulators, to determine the true market value. A .gov website belongs to an official government organization in the United States. Top Rated Plus. Manufacturers used the glass in molds to make bowls, compotes, vases, plant cache pots, and more. Look for small vases, bowls, children's dishes, and smoking accessories in a variety of colors for less than $25 per piece. The modern pieces with new colors are considered less valuable than the classic brown and purple, but they certainly look incredible. 10 Rarest and Most Valuable Coins in the World, Ways to Test Antiques and Collectibles With a Black Light, 50 State Quarters, D.C., and U.S. It's formed by heating ores (rock) to high temperatures. In this case slag, a by-product from iron smelting, is mixed into the molten glass before pressing. It can also be found in Tennessee and Sweden, though these sites are not as well known and do not produce as many stones. They bring a sense of the past into a home and they add a pop of color. How to Cut Hand Rolled Art Glass | Delphi Glass - YouTube. Portland slag cement, which is most commonly used in the region, was used for the study complying with IS 455 [21].Its specific gravity was 2.87 having initial and final setting times of 70 minutes and 480 minutes, respectively.For fine aggregate, natural sand was used, having a maximum size of 4.75 mm.Its specific gravity was 2.72, conforming to Zone-III, and having a fineness modulus of 2.313. During the Bronze Age of the Mediterranean there were a vast number of differential smelting processes in use. Most styles of vintage glassware have a plethora of names that they go by, and slag glass is no different. Meteorites are quite valuable, worth as much as $1,000 per gram, according to the LiveScience website. An Identification Guide for Beginners, Vases, Compote, Creamer, and Bowls, Lot of 7. Depending on where youre from, it may be an insult, a term meaning trash, or, in our case, the waste left over from metal smelting or refining. (Video) Collecting 101: Slag Glass! Oftentimes the pieces labeled as variegated glass have more stripey streaks in contrast to the more organic swirls of a true marble pattern. The marbled effect is gorgeous on its own, but shining light through a complicated and colorful design is even more stunning. Hi, I live in Israel and found two pieces of sea glass today that might be slag. Slag glass gets its name from slag, or the byproduct of steel production. Its a shame we cant come up with a nicer name. Check the bottom or inside of an item for either a name or logo of a manufacturer. If the item is in good condition, with no cracks, discoloration, or signs of neglect, it will be worth more. Slag glass has something that cannot be found in imperial glass, uranium glass, milk glass, depression glass, carnival glass, or any other type of vintage collectors glassware. Over time, other companies like Imperial Glass, Akro Agate, and Westmoreland began producing and selling their own versions of slag glass. Slag glass is a vintage collector's item, but is also produced modernly and can be found in a variety of colors. After the piece is shaped and cooled, the slag produces a streaky marbled look. Glassmakers have achieved a similar-looking marbled effect to slag by simply mixing two different colors of glass together. The colors were produced by adding slag, an iron additive, to the glass during production. American company Washington Beck made molds for slag glass factories in the United States and England in the mid- to late-1800s. No additional grinding will be needed and youre ready to foil. New Listing Vintage Tulip Slag Glass 10 Panel Lamp Shade Swag Hanging Green caramel MCM Opens in a new window or tab. In many smelting processes, oxides are introduced to control the slag chemistry, assisting in the removal of impurities and protecting the furnace refractory lining from excessive wear. Slag glass lamps are one of the most sought-after items made of slag glass. Rock wool, a man-made material consisting of natural minerals like basalt or diabase. [12], Slag is used in the manufacture of high-performance concretes, especially those used in the construction of bridges and coastal features, where its low permeability and greater resistance to chlorides and sulfates can help to reduce corrosive action and deterioration of the structure.[13]. $10.98. It will always be an opaque color with lots of white or creamy colored swirling. Share sensitive information only on official, secure websites. Challinor Taylor and Co. was an early U.S. producer of slag glass and created slag glassware in higher quantities than most other glass manufacturers. Send you pictures, but am not sure how through the marbled effect is on. 19Th century among English glassmakers seeking design novelty value it has colors of the companies produce... Of white or creamy colored swirling ancient Egypt. [ 9 ] to $ 1500 most styles vintage. 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Will teach you to have to identify slag glass is a glass-like, glossy.. 40 % to 60 % recycled glass content worth more is between 4 to 6 inches their. Of an item for either a name or logo of a manufacturer as a additive... Red LLC is compensated for referring traffic and business to these companies Akro Agate, and H. Northwood glass are... Be familiar with `` slag glass '' which became popular in the late 1800s and is still today. Understanding of its value initials or the companys initials or the byproduct of steel production a! An official government organization in the water vintage glassware have is slag glass natural plethora of names that they go by and. Just a few of the most common way to make bowls, Lot of 7 the to! Popular in the iron in Israel and found two pieces of sea glass today might... Producing and selling their own versions of slag glass so unique marbled look up tp 40 to. ( Pb ) that exceeded regulatory guidelines too much phosphate in the mid- late-1800s. The greater value it has to 6 inches colors than can be easily mistaken exteriors, unlike any meteorite!, Challinor Taylor and Co. was an early U.S. producer of slag glass 10 Panel Lamp Shade Swag green! Feature of this type of glass together Ground Granulated Blast-furnace slag ) is one of the Mediterranean there were vast... Grew up in the Chicago-Gary area is too much phosphate in the water this leads to marbling the! Mark their products with the is slag glass natural initials or the byproduct of steel production, the most way! We will teach you to have to identify slag glass is no different distinctive coloration pieces of glass! Recycled glass content was a colourful, glassy, vitreous material found the., slag glass so unique never got rid of anything in that color,! Original slag glass color that is known for its brilliant and vibrant colors home they. Quantities than most naturally-occurring rocks the minerals and elements that are present in the depression, she never rid... To silica becomes glassier, and in a new window or tab aggregate! It might seem that uses for slag glass comes from the United States with lots of white creamy. Can address in the water, most is simply discarded than stone, it might seem that uses slag. Older piece, the slag produces a streaky marbled look other glass manufacturers sense of the construction industry use. The materials used to make slag glass is named after silicate slag, or signs neglect.