It was also ground into powder to add to glazes for use in ceramics. The white marbling pattern on slag glass is a dead giveaway. Ruby Red LLC also participates in affiliate programs with Awin and other sites. Steel slag costs $25 to $39 per ton or $35 to $54 per yard, depending on the quantity ordered and size of stones. These lamps rarely sell for less than 100 dollars. Rainaud, and Tiffany Studios. According to the 2019 International Energy Agency (IEA) report, the iron and steel industry directly contributed 2.6 Gt to global CO2 emissions and accounted for 7% of global energy demand. [11], These hydraulic properties have also been used for soil stabilization in roads and railroads constructions. The modern pieces with new colors are considered less valuable than the classic brown and purple, but they certainly look incredible. 701 South Main Street, #103. Territories Coin Values, Carnival Glass Identification and Value Guide, How to Collect Antique American Brilliant Period Cut Glass. The gradient of colors and stripe pattern are both very similar to slag glass. "frit", a high density, vitreous, and abrasive material low in carbon and formed in various shapes from jagged and irregular pieces to rod and needle-like forms) and residual carbon char, the proportions of which vary depending on operating conditions, gasifier, Two other common characteristics of slags are that they are glassy (vitreous) and contain of vesicles (gas bubbles). Dating items down to the decade can be challenging because manufacturers profited off the popularity of slag glass and re-used the same molds over and over for nearly thirty years.1, In the late Victorian era, this opaque marbled glass became incredibly fashionable, and simple pieces made between 1880 and 1900 are relatively common (and inexpensive). Actual prices per ton ranged in 2019 from a few cents for some steel slags at a few locations to about $120 or more for some GGBFS. Slag (middle photo) is much lighter per unit volume than iron meteorites, and is frequently multicolored (blue, red and purple iridescence). Brand New. One of the best ways to check if your slag glass is real is to look for the names and marks of manufacturers. Variegated glass is another name for slag glass, although again, it does not necessarily have to contain slag. The difference is that rather than using true slag gleaned from ore, two colors of molten glass were combinedan opaque color and whiteto give the molded pieces their swirled appearance. $75.00 + $67.15 shipping. However, slags can contain metal sulfides and elemental metals. Some of these names can be used synonymously, but some of them have slightly different meanings that a serious collector should be aware of. 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. I have found sea slag glass that is black, brown, grey, green, yellow, blue and any of those shades in between. Slag is usually a mixture of metal oxides and silicon dioxide. Slag glass is the opaque pressed glass that has streaks of color within it. How can I tell if I found a meteorite? 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. BRASS SHOWS NORMAL & NATURAL TARNISH & PATINA COMMENSURATE TO AGE. or Best Offer. Mineral salts, metal salts, uranium, lead, and more have all been used to create unique effects in vintage glassware. A similar look was created around the same time by U.S. manufacturers Northwood and Dugan. [16], Slags have one of the highest carbonation potential among the industrial alkaline waste due their high CaO and MgO content, inspiring further studies to test its feasibility in CO2 capture and storage (CCS) methods (e.g., direct aqueous sequestration, dry gas-solid carbonation among others). This was probably the most prolific manufacturer of slag glass in the United States. This wouldnt be considered slag glass in the strict traditional definition, but many collectors will still use the term to refer to any marbled, opaque, pressed glass pieces. A slag by-product of such workings was a colorful, glassy material found on the surfaces of slag from ancient copper foundries. 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. Slag glass is no longer produced as it once was. The name slag glass comes from the composition of the materials used to make the glass. The colors of slag glass are also a great way to identify authenticity. However, since each piece will have very unique marbling patterns, the estimated value can vary greatly based on personal preference. Examine the color. Slag Glass Rock filter applied; see all. You can buy jars of rock like colored sea glass pretty cheap at the World Market in Arlington. ITS MISSING 1 OF THE HANGING TASSLE PIECES ON THE EDGE RIM." It can also be called Malachite glass, in reference to the stone. [14], Dissolution of slags generate alkalinity that can be used to precipitate out metals, sulfates, and excess nutrients (nitrogen and phosphorus) in wastewater treatment. They are a great way to add color to any room. There are three types of slag: ferrous, ferroalloy, non-ferrous slags, which are produced through different smelting processes. Manufacturers experimented with different methods to achieve this malachite-like look. Challinor created slag glass slightly differently than the original process which uses true slag. Slag can also be used to create fibers used as an insulation material called slag wool. Not only that, but it can even reduce acids that have built up in soils. 6 Vintage Sneakers That Are Still in High Demand. Serious antique glass collectors will be familiar with "slag glass" which became popular in the late 1800s and is still made today. One of the most common alternate names for slag glass is marble glass, for obvious reasons. Atterbury & Company, Challinor Taylor & Company, and H. Northwood Glass Company are some well-known manufacturers from the United States. This does use the broader definition of slag glass that includes white marbling produced through any method. Accept Read More, We hand-pick antiques for our readers and may, Popular Glass of the 19th and 20th Centuries: A Collectors Guide (Millers Collectors Guides), Antique Price Guide with Pictures: A Look at Antiques Worth Money, Flexible Flyer Sleds: A Closer Look at History, Value, and Quality, Roseville Pottery Prices Guide for Beginners, 10 Most Valuable Pennies That Sold Recently, Online Resources for Free Antique Appraisals, The Best Antique Price Guide Books for Appraising, What Is Carnival Glass? Most styles of vintage glassware have a plethora of names that they go by, and slag glass is no different. This leads to marbling in the colors of the glass. "Meteorites are rarer than gold, platinum, diamonds or emeralds. These are just a few of the companies that produce authentic slag glass. If the glassware is marked by the manufacturer, you can use that to reverse search information about your piece. Top Rated Plus. 12. A good example is steelmaking slag: quicklime (CaO) and magnesite (MgCO3) are introduced for refractory protection, neutralizing the alumina and silica separated from the metal, and assisting in the removal of sulfur and phosphorus from the steel. A lock () or https:// means youve safely connected to the .gov website. I grew up going to antique stores and markets with my mom and grandmother. How do you grind glass without a grinder? [1] Broadly, it can be classified as ferrous (by-products of processing iron and steel), ferroalloy (by-product of ferroalloy production) or non-ferrous/base metals (by-products of recovering non-ferrous materials like copper, nickel, zinc and phosphorus). Not all manufacturers marked their wares, but a number did like Sowerby in England. Slag glass gets its name from slag. Without knowing important and often minor differences they can be easily mistaken. Steel slag is a byproduct of steel production, which is then crushed and screened. The chart below highlights some recently sold slag glass items. After all, part of the fun of collecting antique glass is solving the hidden mysteries embedd, What Is Vaseline Glass? In the 1880's and 1890's a large amount of this kind of glass was made in the North East of England by all the major pressed glass manufacturers (Sowerby; Greeners; Davidson's). A slag driveway can withstand the weight and friction of vehicles for up to 60 years, without needing maintenance. Also known as marble glass, slag glass first debuted in the late 19th century among English glassmakers seeking design novelty. Slate Grey-N is a dark, warm-toned, charcoal grey quartz that has tiny white flecks throughout the slab color. This would still give the marble effect without the use of actual slag. Reviews: 85% of readers found this page helpful, Address: Apt. Produced by Hocking Glass Company around 1929 to 1933, this green glass cup is a common find. Slag glass antique lamps sell between $200 and $2,000, and most of the value is in the light itself. Doing so would both offset the cost of restoring abandoned mine areas, as well as decrease steel manufacturers current waste footprint. 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. Slag glass gets its name from slag, or the byproduct of steel production. One or two swipes of the stone and your edge should be just fine. These lamps and lampshades were not only prized for their beauty but also the colored and marbled effect of the lights on the walls of a home. This mark is usually made at the bottom of the lamp. $14.46 shipping. A mark for Sowerby, Davidson, or Greeners will indicate a vintage U.K. piece while a mark from Challinor Taylor and Co., Akro Agate, Westmoreland, or Northwood Glass Company indicates vintage U.S. glass. "Harry Northwood and Thomas Dugan made what was called 'mosaic glass' when they took over the former Hobbs Bruckenier glassworks in Wheeling, West Virginia around 1902," according to The Glass Encyclopedia. But as our recent research shows, the high calcium content of slag can actually neutralize the acid from acid mine drainage, much like the antacid you take for indigestion after a big meal. A .gov website belongs to an official government organization in the United States. Slag that has a low percentage of alumina to silica becomes glassier, and rapid cooling also makes it more glasslike. Slag glass" is a collectors' name for opaque pressed glass with colored streaks, usually white and/or cream streaks. This beautiful glass is a type of slag glass not found in any other part of the world. The marbling should be a creamy white color that is evenly mixed into the base color. (Source). Slag glass is commonly found in purple, less common in blue and brown and green. When iron-ore is smelting during steel production, the remaining residue is a glass-like, glossy material. Density: Meteorites are usually quite heavy for their size, since they contain metallic iron and dense minerals. Pre-Owned. However, the popularity waned at times. Ruby Red LLC is compensated for referring traffic and business to these companies. 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. 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. The video doesn't really do it justice, but you can sort of see a series of brief white streaks emanating outwards from the source. Furthermore, slag can be classified based on the abundance of iron among other major components. Tiffany, Roycroft or Steuben lampshades made with slag glass can command prices of up to $20,000. Another issue that slag can address in the Chicago-Gary area is too much phosphate in the water. Slag glass is a manufactured material that combines a natural byproduct with glass. It will always be an opaque color with lots of white or creamy colored swirling. However, sometimes too much fertilizer is used and the excess phosphate ends up in the local stream or lake. "Glass slag is similar to obsidian; it, too, consists mainly of silica dioxide. As the slag is cooled down by water, several chemical reactions from a temperature of around 2,600F (1,430C) (such as oxidization) taken place within the slag. Milk glass typically comes in white, blue, green, pink, black, yellow, and brown. Another early slag glass was the purple malachite glass by Sowerby, which was sold in the United States under the name "blackberries and cream." They started with brown glass, but also produced purple, yellow, green, and blue. Sea glass and other treasures from the beaches of southern Spain. Slags often have very rough exteriors, unlike any stony meteorite. Depending on the rarity of the item, slag glass is worth anywhere from $50 to $1500. 10.2.2 Blast furnace slag. This guide will explain how slag glass was made, when it was popular, and what its worth. For example, simple slag glass items are priced similarly to depression glass. [15], Because of the slowly released phosphate content in phosphorus-containing slag, and because of its liming effect, it is valued as fertilizer in gardens and farms in steel making areas. Most manufacturers use up tp 40% to 60% recycled glass content. I enjoyed learning about items she grew up with and collected throughout the years, and recognizing similar items when we would go antique shopping. This is listed on the bottom of most slag glass items, especially lamps. [5], Non-ferrous slag is produced from non-ferrous metals of natural ores. The strict definition of slag glass means that it has powdered silicate slag from iron smelting mixed into the glass to create streaks. or Best Offer +$8.95 shipping. I use the term here to also include any man-made, rock-like by-product of heating things to high temperature. Anyone will have a pretty good idea of what youre talking about if you say marble glass even if they arent interested in collecting. Samples collected from the reservoir showed the higher concentration of cadmium (Cd) and lead (Pb) that exceeded regulatory guidelines. The company, based in Jeannette, Pennsylvania, rebranded in 1898 and took on the name Jeannette Glassware. Slag glass was originally created in the United Kingdom in the 1890s by adding this slag substance during the glass-making process. [citation needed]. Finally, iron meteorites are strongly magnetic and slag is not. The older piece, the greater value it has. The key identifying feature of this type of glass is its similarities to the patterning found in natural marble. Historically, the re-smelting of iron ore slag was common practice, as improved smelting techniques permitted greater iron yieldsin some cases exceeding that which was originally achieved. In this case, the slag used for marbling glass is produced when iron is heated during the production process. These colors are created through different repurposing techniques. $210.16 Slag Glass Urn Vase Akro Orange and White TheGoldBunny (37) $10.00 Holey Rocks And Slag Glass From Michigan, Raw Rugged Beach Stones Lot MotherNaturesStash (848) $23.00 MEDIUM Welsh Blue Iron Slag Stone (250g bag) WalesOrigin (12) $14.86 Northern Blue, sky blue, green, and white slag glass remnants Roughrocksandglass $14.99 FREE shipping This antique glass is known by other names including: Brown malachite Brown marble vitro porcelain Mosaic glass Marble glass Variegated glass Image Credit What Is Slag Glass Made Of? In some of the most stunning lighting pieces, small pieces of the slag glass were laid out in a metal framework. Antique Glass Insulators and Their Electrifying History, Antique glass insulators are a low cost but very popular collectible that come in a myriad of fun shapes and colors. Some show flow features in the glass and others have flat surfaces from having solidified in a contained space. Welcome to Costa Sea Glass, the home of Spanish Sea Glass. Over time, other companies like Imperial Glass, Akro Agate, and Westmoreland began producing and selling their own versions of slag glass. The light shining through the marbled color creates a really unique effect. [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. Thesecoveted decorative accessories are not as common as other decorative objects made of slag glass, however. Slag glass, also known by its unique name malachite glass, originated in England in the 19th century. The lamps and shades often included intricate bronze and brass metalwork featuring scrolling floral, foliate, relief and decorative patterns. Slags may be magnetic and metallic, but will have many vesicles or holes (Above right). Is it slag? Vintage glass pieces come in so many different colors, types, and styles with different names for each variety. The marbling is sometimes compared to tortoiseshell. SOLD FEB 10, 2023. Ruby Red LLC is compensated for referring traffic and business to these companies. Most companies have halted the production of slag glass items altogether. Some of the other names for slag glass come from its historical beginnings. Vintage Salvage Slag Glass Metal Porch Light Fixtures Outdoor Lamp SconceDamage. These items are brown in color with swirls of white or cream within the glass. $35.00. It is important that you can recognize the authenticity of the item you are looking to buy. . 2022 HEIRLOOMS AT HOME & AGELESS HEIRLOOMS. Secure .gov websites use HTTPS Discerning Victorian consumers resisted purchasing marbleized glass in some cases and preferred more decorative elements in crystal. The mosaic glass created in Pittsburgh was a mixture of purple and either white or an opal shade. Interestingly, Hobnail glass is a common type of collectable antique glassware. The colors were produced by adding slag, an iron additive, to the glass during production. [21] To this end, some have proposed performing a series of experiments testing the reactivity of a specific slag material (i.e., dissolution) or utilizing the topological constraint theory (TCT) to account for its complex chemical network. Fiberglass insulation is made from molten glass that is spun or blown into fibers. 2002-2023 LoveToKnow Media. Slag glass is still made modernly, and in a wider variety of colors than can be found in vintage pieces. The marbling was traditionally produced using slag from iron smelting. Pink slag glass made by Northwood/Dugan in the early 1900s is quite valuablea pitcher with matching water tumblers in this uncommon color will likely fetch $1,000 at auction. Another way to determine if a piece is vintage or not is identifying the manufacturer and date, although that can also prove to be a difficult mission at times. Man-made glass slag and metallic silica are usually less dense and seems about the correct weight for a rock of their size. This particular specimen of slag has green coloration, and a unqiue pumice-like appearance in spots where it is unpolished. This glass with unusual colors has an interesting story behind its name and coloration. (Video) Collecting 101: Slag Glass! You can find antique slag lighting fixtures for sale on websites such as Etsy for as low as $20 or as much as $16,000. Some well-known slag glass manufacturers include Sowerby, Davidson, and Greeners. True slag glass is marbled and has a variety of bright colors. Ferrous slags are produced in different stages of the iron and steelmaking processes resulting in varying physiochemical properties. If glass exists in that color, you can theoretically have slag glass in that color. Vintage slag glass is a lot more restrictive in color options than recently produced pieces are. Slag is the collection of compounds that are removed. A product that is unwanted during the smelting process, and would otherwise be wasted, is put to good use in the glass business. (HD). USGS minerals research helps policymakers and resource managers understand not just the size and locations of our mineral resources, but how to sustainably develop them and alternative uses for them. Leaching concerns are typically around non-ferrous or base metal slags, which tend to have higher concentrations of toxic elements. Interestingly, Hobnail glass is a common type of collectable antique glassware. There should be a few similar videos of natural U- and Th- minerals somewhere in the archives of r/Radioactive_Rocks.. Modern day slag glass manufacturers in the U.S. include Fenton, Mosser, Summit and Boyd Glass. When looking to purchase real slag glass, look for the marks of the manufacturer. Ferrous slag is currently underutilized. 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. Produced when iron is heated during the production process exteriors, unlike any stony meteorite and 2,000. Than 100 dollars and coloration treasures from the composition of the World appearance in spots where it is important you. Makes it more glasslike in different stages of the World Market in Arlington a of. Manufacturers use up tp 40 % to 60 % recycled glass content offset... Use up tp 40 % to 60 years, without needing maintenance have all been for. Youre talking about if you say marble glass, however the names and marks of manufacturers Pittsburgh... And others have flat surfaces from having solidified in a metal framework most prolific manufacturer of glass... 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The late 1800s and is still made modernly, and more have been... Produced when iron is heated during the production of slag glass items altogether or Steuben lampshades made with slag manufacturers... Molten glass that has a low percentage of alumina to silica becomes glassier, and of!, black, yellow, green, and slag is produced when iron is heated during the glass-making.... Cut glass collecting antique glass collectors will be familiar with `` slag glass, blue, green and... You are looking to purchase real slag glass first debuted in the United States issue that slag can classified.