Tuesday, August 26, 2014

Fossil shell geodes

Partial fossil geode from Rio Dell, California
Ever found a fossilized shell that broke open and revealed hundreds of bright yellow crystals growing inside it, like a tiny geode?

They're usually calcite crystals that grew inside the hollow of the shell during the fossilization process -- since fossils are frequently preserved by calcite, there's an abundance of the mineral around to create the crystals.

The one above I found at Rio Dell, California -- I saw quite a few of broken ones, and probably some of my nice complete fossils have crystal vugs within them as well, although I haven't wanted to break them open and find out!

Tuesday, August 19, 2014

Mineral of the Day: Aquamarine

Aquamarine is the blue variety of the gemstone beryl, which comes in a number of different colors [Green is emeralds, golden is heliodor, colorless is goshenite, pink is morganite, and red is, well, red beryl]. The coloration differences are caused by impurities within the beryl.

Aquamarine is probably the most common, and can be found in most beryl-bearing localities. That isn't to say that it's all over the place, but it's a fairly accessible gemstone to buy. Crystals from Brazil and Pakistan are usually inexpensive, although one must be aware that they have often been irradiated to enhance the blue coloration.

Tuesday, August 12, 2014

Mystery mineral

I ran across these photos while I was cleaning out an old hard drive. Some years back, I had a job sorting and identifying a bunch of specimens that had been donated to the local college, and these were among them.

I never could figure out what they were. They're very heavy and definitely metallic, with a grayish streak. Anyone got ideas?

Saturday, July 26, 2014

Mineral of the Day: Dogtooth Calcite

Calcite is one of those minerals that can be baffling to a beginning collector, due to its myriad of different forms and colors. But it is a mineral well worth knowing -- fairly common and usually inexpensive yet lovely.

The calcite here is what is often know as "dogtooth" calcite after the shape of the crystals. The reddish color in this case comes from inclusions of hematite.

This particular specimen is from Santa Eulalia, Chihuahua, Mexico.

Sunday, June 15, 2014

Tips and Tricks for Making Jewelry

Hello to everyone on  "Rockhound Times", and many thanks to Krissa for the offer to be a guest blogger here.

My name is Brad Smith. As background, I'm a studio jeweler, lapidary, author, and jewelry instructor in Santa Monica, CA. Currently, I'm also President of the Culver City Rock and Mineral Club and Show Chair for their Fiesta of Gems Show coming up on June 28 & 29. If you're nearby, please stop in and say hello.

I've done a lot of rockhounding since moving to California and joining the club. Liked it so much that I started the LA-Rocks discussion list to find more field trips to join. It's a good forum to hear what's going on around LA and to to get questions answered about lapidary equipment.

My journey into rockhounding quickly led me to the lapidary shop and cutting a lot of gemstones. That of course, led me to a silversmithing class, and the combination of the two has been one of the pleasures of my life ever since.

With that as a brief introduction, let me get to the subject of the material that I'll sharing with you. Many rockhounds make jewelry to show off their work, and what I'd like to do is to pass on some tips to improve your skills and help you be more productive. These are tricks of the trade for improving quality and saving time from my 18 years of teaching hundreds of students.

Every profession has it's tricks and Tips.  Here's some of mine.


When bezel setting a cab that has rather sharp corners, have you ever had problems pushing the metal down at the corners? It's a common problem often causing a wrinkle in your bezel. 

In order for a bezel to capture the stone, the top edge of the bezel must be compressed and become shorter to lay down onto the stone.  With a round or oval stone this naturally happens as you push and burnish the bezel. But when setting a stone with corners, the tendency is to push the long sides of the bezel down first. No compression occurs along the sides, and all excess metal is left at the corners. Compressing everything there is difficult. Often the only way to remove the extra metal at the corner is to make a saw cut and fold the two sides in to touch.

If you want a smooth bezel all around the corners, the simple solution is to set the corners of the bezel first. Then push in and burnish the sides.  In this way the necessary compression is distributed along the length of all sides and not forced to occur at the corners. With the corners set first, the top edge of the bezel can easily be compressed along the sides.


Cutoff wheels are inexpensive and in a Foredom or Dremel do a great job cutting or shaping steel.  You can use them to sharpen tool points, cut piano wire to length, make slots, and sharpen worn drills. Other uses include modifying pliers and making your own design stamps.

My preference is the one inch diameter size.   Be sure to hold the wheel firmly so nothing moves to break the disk, and definitely wear your safety glasses.  Those are little flakes of steel coming off the disk.

BTW - Cutoff wheels are poor at soft metals like copper, silver and gold. Soft metals clog up the cutting edges.

Get all 101 tips in "Bench Tips for Jewelry Making" on Amazon.

Multiple five star reviews.  Written for beginner to advanced jewelers, the book is filled with tips to improve soldering, how to avoid common hazards, suggestions for making your own equipment, and sources for inexpensive tools, plus over 80 close-up photos that show you exactly how to do it.