Strata Gem

July & August 2005

 

President’s Message

 

Just a recap of the summer. Our grab bag fill in June was a success. We planned a field to a mine dump out of Eureka. Some new people heard about it on the Internet and showed up. We made plans for a trip in July. This was cancelled due to the heat and will be scheduled later. My apologies to Tony and Vickie Roberts who were not notified of the cancellation and showed up. They called and said they would just go on out to the trilobite beds. Hope you had a great time. Don't forget our steak fry on August 20th. See you there.

 

Bob Titus

President

 

June Minutes

Held In Conjunction With Grab Bag Fill

June 4th 2005

 

The meeting was called to order by President Bob Titus, he thanked everyone for coming out to help with the rock bags and crafts. Larry Higley has found another supplier for our badges, he brought the new badges we had on order they have a desert scene engraved on them along with the persons name, and they will coast $7 each. The minutes and treasurers report will be given at our next meeting. It was reported that our last field trip was a success we got a lot of zebra rock and had a good time; our next trip will be to Eureka on June eighteenth. The tickets for the prizes at our show were passed out, and we were admonished to sell a bunch, it was decided to get a barbecue for our grand prize, and we will have two Afghans for the closing prizes on Friday and Saturday, these were made for us by Melva Scott. We discussed who we should have to cut the ribbon for the opening of our show no final decision was made. It was decided to discuss security arrangements at our next meeting.

Larry Higley ask that those who need a case for the show should call him to reserve one, we need to check our case liners and repair and replace them as necessary. One of our dealers has canceled so we will have a demonstrator to replace him.

The next meeting will be our steak fry, the meeting was adjourned.

 

Minutes Submitted by

Larry Wilson Secretary.

 

Tooele Gem & Mineral Annual Steak Fry

Saturday August 20, 5:00 PM

Settlement Canyon Pavilion

 

Our Steak Fry & August meeting will be at 5:00 PM Saturday August 20, at the Pavilion in Settlement Canyon, Tooele. Come early to help set up. You will need a potluck dish, bring plates & utensils, chairs if wanted. The Club will supply steak, corn & drinks. Steaks are free for members, guest are $6.

 

Reservations need to be made by Aug 10.

 

Old News Is Still Good News

Gems That Can Stand Heat

 

Among the precious stones the ruby the sapphire, spinel and various kinds of garnets can be heated. In answering this question it is always to be presumed that such heating is done with great caution and that such stones when heated are cooled very slowly and that they are not exposed when hot to contact with fluids or cold air.

The diamond also may be exposed to great heat but only at the risk of an increase of the extent of defective marks, cracks and the injury of polished surface. Therefore such heating is to be avoided as much as possible especially when stones of good size are in question.

Emeralds, aquamarine, topaz, hyacinth and some others cannot be exposed to heat as some of these would lose their color and opaque and translucent specimens would be cracked by artificial heat.

 

Emery County Progress 1906-10-06

via Utah Digital Newspapers

 

Coin Composition

 

When the U. S. Mint was established in 1792, the law required that all coins be made of gold, silver or copper for a considerable period of time afterwards, gold was used in the $10, $5 and $2.50 pieces, silver was used to make the dollar, half-dollar, quarter, dime and half-dime while the penny and half-cent coins were made of copper.

In 1933, during the Great Depression, the U.S. Mint stopped making gold coins altogether. In 1965, as a result of a severe silver shortage, Congress dictated that silver no longer be used in making quarters and dimes. In addition, the silver content of the half-dollar (previously 90%) was reduced to 40% in 1965 and eliminated entirely in 1971.

In order to make modern coins, the U.S. Mint purchases strips of metal (rolled into coils) in the proper dimensions and thicknesses. Zinc metal strips (coated with a copper plating) are used to make pennies. Strips used for nickels are comprised of a 75% copper, 25% nickel metal alloy. Dimes, quarters, half-dollars and dollar coins are produced of strips consisting of three metallic layers fused together. The outer layers of these strips are comprised of the same alloy as that used for nickels with the third (core) layer, being comprised of copper.

The first step in the coin making process involves the feeding of the metal strips through what is known as a 'blanking" press. This press punches out cut round discs (blanks) about the same size as the finished coin. These blanks are then heated in a furnace to soften them, placed in rotating barrels of chemical solutions for cleaning and polishing, then washed and dried.

Next, the blanks are sorted to remove any defective ones and the balance are put through an "upsetting" mill, which raises a rim around their edges. The rimmed blanks then go to the coining or stamping press where upper and lower dies stamp the designs and inscriptions on both sides of the coin. At this point, the blanks become genuine U.S. coins.

Finally, the finished coins are mechanically counted and placed into large canvas bags for shipment to the Federal Reserve Banks. From there they are shipped to local banks as needed.

 

http://coins.about.com/library/weekly/aa030100a.htm

via The Sooner Rockologist, 5/03

Sue Smith is a member of the Oklahoma Mineral and Gem Soc.

via The Glacial Drifter 4/05

Tech Talk

By Val Carver, MMC Member

 

This Months Article: TYPES OF SAWS

 

There are 3 basic classifications of lapidary saws, these are:

A.Faceter's Saw

B.Trim Saw

C.Slab Saw

 

Faceter's saws are primarily used to prep small chunks of rocks for faceting. Faceter's saws can sometimes be used for VERY LIGHT trim saw work. Usually they have blade sizes in the 4" to 5" diameter range and are usually manually feed. These types of saws are tabletop mounted units. Prices for faceter's saws are normally in the $200.00 to $300.00 range. Most faceter's saws are designed to be used with water and water based lubricants.

Trim Saws are used to reduce the size of a chunk of rock. This type of saw is normally used to cut cabochon performs from materials that have been slabbed. They can also sometime be used for light slab work or to cut a rock in half. Most trim saws are manually feed, some have vices to chuck up a rock. Trim saws usually come in blade diameters (sizes) of 6", 8" and 10". These saws are tabletop mounted units. Prices for trim saws range from $400.00 for the 6" size to $975.00 for a 10" sized unit. Depending on the construction of the saw they will require either water-based lubricants or oil lubricants. Into this classification of saw can be included saws like ring saws, diamond band saws and scroll saws.

Slab saws are the big boys of the saw world. They are used to take large chunks of rocks and normally make slabs out of them. A slab is defined as a piece of rock cut with parallel surfaces. Slabs are typically cut 1/8" thick to several inches thick. Normally slabs are cut ¹/4" to 3/8" thick for cabbing. Slab saws come in blade diameter sizes of 10", 12^", 14^", 16^", 18^", 20", 24", 30" and 36". The 10" through 14" units are normally tabletop units while the 18" and larger are stand-alone units. Price ranges for new slab saws are from $900.00 for a 10" unit to $15,000.00 for the 36" size. The function that makes a slab saw a slab saw is that the rock is chucked up in a vice and is fed into the rotating blade by some type of a feed drive mechanism. The slab saw also has a transverse table feed so that after you have cut a slab you back the rock out and without un-chucking the rock move it over with a crank on the table to cut another slab. ALL slab saws should ONLY be used with oil lubricant.

 

Via The Rock Rustler's News 4/05

 

From The ROCKHOUND's Dictionary:

 

·        Diamond: The hardest stone known to man to get back from his old girlfriend.

·        Faceting: A complex way to ruin a good mineral.

·        Findings: Stuff you find.

·        Fortification: Two & twentyfications; A large gulp of good whiskey.

·        Friend: One who can see the star in your sapphire.

·        Gentleman: A man who holds the door open for his wife to carry the rocks in.

·        Geode: A poem to G. (often written in hollow verse)

·        Grinding Wheel: A bearing going out on your old truck.

 

Via: The Pegmatite, May 2004

Via Beehive Buzzer July/Aug 2004

 

Ancient Origins Of The Lapidary Arts

By Allen L Lundgren, MMC Member

 

Those of us who collect, cut, polish, and otherwise work with stones and make jewelry and do related lapidary work, seldom think about how old this interest in ^"stones^" really is. By ^"stones^" I mean to include all of the rocks, minerals, and fossils we commonly find of interest. But many historical and archeological sources tell us that our interest in lapidary and related arts has been a part of human life for thousands of years.

We don^'t know when or where the first interesting and attractive stones were collected. It was obviously long before recorded history. Many semiprecious stone objects, such as fetishes and necklaces, have been found in stone-age graves in many places of the world. Some were probably collected and kept because they were thought to have magical powers: others simply because they were beautiful. (1)

Many are familiar with the directions recorded in the Bible (2), Exodus 28, for constructing holy garments for Aaron, the brother of Moses. The detailed directions given indicate that at this early age (generally agreed to be in the 13th century BC), the engraving of precious and semiprecious stones and the making of fine gold jewelry were already well known.

Exodus 28 describes the making of the ephod, or outer vestment in this manner:

Exodus 28 (9-11): ^"And you shall take two onyx stones, and engrave on them the names of the sons of Israel, six of their names on the one stone, and the names of the remaining six on the other stone, in the order of their birth. As a jeweler engraves signets, so shall you engrave the two stones ... you shall enclose them in settings of gold filigree.^"

Exodus 28 (13-14): “And you shall make settings of gold filigree, and two chains of pure gold, twisted like cords ...”

These two stones were to be set on the shoulder pieces of the garment.

Exodus 28 also describes in great detail how to construct a breastplate to be worn by Aaron as part of his priestly garments, mentioning 12 different stones in four rows. The first row includes sardius, topaz, and carbuncle: the second row, emerald, sapphire, and diamond; the third row jacinth, agate, and amethyst; and the fourth row beryl, onyx, and jasper.

Exodus 28 (20-21) continues: ^"they shall be set in gold filigree. There shall be twelve stones with their names according to the names of the sons of Israel; they shall be like signets, each engraved with its name, for the twelve tribes.^"

There is some uncertainty about the exact identity of the stories mentioned in the original texts, depending upon the translated version of the bible used, whether the Hebrew, Greek, Aramaic, or Latin. The stones named above were the names as given in the Revised Standard Version of the bible. The same list of stories (with one exception) is given in the earlier King James version of the bible. This biblical passage is an early literary recognition of accomplished lapidary arts, and the use of a wide variety of precious and semi-precious stones for adornment during that period.

There is much evidence of earlier examples of the lapidary arts. Some of the earliest examples of craftsmanship in stone carving are carved cylinder seals, dating back before 2,000 BC. Found in many archaeological excavations around the world, they have contributed much to a better understanding of history, and tell us much about early lapidary work.

Cylinder seals were small cylinders of horn. ivory, or semiprecious stone, that were engraved with intricately carved scenes or other figures. Some had figures or inscriptions on them. Most were unique to a particular person or office. Rolling a round seal on an inscribed clay tablet, for example. could indicate that the owner of the seal had authenticated the business transaction, or legal document described. Babylonia, during the Uruk period (roughly 2700 to 2600 BC) has been credited for introducing the use of the cylinder seal. Cylinder seals were about 1 inch to 1 1/2 inch in length. Other seals were also in use, including flat squares, such as an engraved small stamp or ring stone, that were meant to be stamped or pressed on a document leave an impression. It took special skills to carve a reverse inscription on a seal so that it would leave a clear legible impression when used.

Precious objects found during the excavation of the royal tombs at Ur, Babylonia (3), during this same Uruk period, indicated that even at this early date there were craftsmen highly skilled in the intricate engraving and carving of stone, gold, and silver. For example, among the tomb objects found at Ur was a gold dagger with an inlaid lapis lazuli hilt that would be the envy of a skilled craftsman today.

It had a gold sheath, fabricated with an intricate design. A number of necklaces, with numerous small semi-precious stories set in gold, were found. Many carved or inscribed amulets and other objects of stone of this period were also found. An engraved gold helmet from this same period shows a high degree of skill in working gold.

Seals dating back to about 2000 BC were found in excavations in the Indus Valley of the Harappan culture, an area now in Pakistan. These Indus Valley seals, with a characteristic design, have also been found in ancient Mesopotamia, suggesting their use in trade. Designs on these seals were usually carved in steatite, a soft stone, which were then fired, to harden them. George Kunz, in his book ^"The Curious Lore of Precious Stones", refers to even earlier examples of carved cylinders dating back to as early as 4,000 BC. They were inscribed with symbols or scenes, and were usually perforated with a hole down the middle of the cylinder, so they could be worn as a necklace. They also may have been used as amulets or talismans, to keep evil away and bring the wearer good luck.

The many gold objects and gemstone carvings from ancient Greece, dating back to the Mycenaean and Minoan civilizations (prior to 500-1000 BC), indicate that the manufacture of sophisticated jewelry was common. Intricate scenes were carved upon stone cylinders in such detail that it requires a magnifying glass to fully appreciate them. Some seal stones found in Crete, related to early Mycenaean and Minoan civilizations, are thought to have originated in Egypt, from their designs. Archaeological explorations of ancient shipwrecks in the Mediterranean have showed that there was much trade among countries, even at this early age.

Mastering this art of fine gemstone carving required years of apprenticeship. Despite the extreme hardness of emerald (7 1/2 to 8), the ancient Egyptians and Greeks were able to engrave them for use as stones in rings (4). 'What these ancient people lacked in tools, they made up for in patience and careful workmanship.

Even in these early times the practice of goldsmithing was highly developed. The process of ^"granulation^", where gold is melted into extremely fine spheres and then applied in clusters for a textured appearance, is well represented in gold jewelry found in Western Asia, Greece, Egypt, and the Aegean Islands dating from the 3rd millennium BC (5). Some of this jewelry is so finely made it is almost beyond belief. It is equal to almost anything being done today.

In Egypt, a tomb dating from the reign of Tuthmosis III, XIIIth Dynasty (about 1490-1436 BC) has a well preserved wall painting of a goldsmith, using a blowpipe, working on a bowl over a fire (6). Other paintings dating from the 18th dynasty clearly show various steps in goldsmithing. Although Egypt had no precious stones within its borders, it did have semi-precious stones such as lapis lazuli, turquoise, amethyst, and carnelian, among others, used to make jewelry, seal stones, and scarabs, among other objects. At times Egypt imported precious stories from other countries. We know that the Egyptians had vast workings in the Sinai desert country for copper, and they have records of visits to that country to get turquoise. Beads of meteoric origin have been found in some tombs of the period.

The few examples given above serve to illustrate that the lapidary arts date back to some of our earliest periods of history. Objects produced by these early artists can be seen in museums or books. When you look at some of the skilled pieces of art these artists produced, several thousand years ago, with primitive methods, you can^'t help but be impressed with their ability. Their work is a challenge to us all.

 

References Cited:

(1)    See, for example, Kunz, George Frederick. 1971. The Curious Lore of Precious Stones. New York: Dover Publications, Inc.

(2)    The Holy Bible; Revised Standard Version. 1953. New York: Thomas Nelson & Sons.

(3)    Saggs, H.W.F. 2000. The Babylonians. London: The Folio Society.

(4)    Gregorietti, Guido. 1969. Jewelry Through the Ages. New York: Crescent Books.

(5)    Gregoriette, Guido. 1969. See above.

(6)    Gardiner, Sir Alan. 2000. The Egyptians; an introduction. London: The Folio Society.

 

Via The Rock Rustler's 5/05