Handcarved Stone Beads

Handcarved Bead Necklace

Finally finished a handcarved stone bead necklace made entirely from pebbles collected in a single canyon in the Santa Rita Mountains.  The photo above was taken in the shade using a flash; a photo taken in natural sunlight is HERE on my Flickr site.  The bead strand is 18.5 inches long, on 20 inches of 4mm leather cord.  I wanted to allow some play in the strand, since the beads are fun to slide around and are big enough that they drape better if they aren’t strung too tight.

The pebbles were cut into blocks on my old trim saw, and were drilled and carved into shape using my Foredom flex-shaft machine and various diamond tools.  Sanding was done by hand with 220, 400, and 600-grit emery paper.  Polishing was done with handmade wooden Foredom tools and several sizes of diamond paste.  Holes were beveled and polished to give a smooth, rounded edge that won’t cut into the cord, so these beads can be strung on almost anything (including braided hair!) without causing damage.  I also like the look of the rounded edge, because it makes the hole an integral part of the bead shape, rather than an afterthought.

Stones include rhyolite and other volcanics (variously altered and oxidized, which accounts for most of the purple, pink and red colors), green epidote and diopside from skarns and metamorphosed volcanics, a blue-green copper ore pebble, a greenstone (metamorphosed basalt) that looks and cuts like black jade (small bead at top left), and a few others.  The four black beads with white flecks are lamprophyre, a volcanic rock that forms small dikes and sills; the beads are from three different dikes, one of which is shown below:

Lamprophyre Outcrop

The black rock at the bottom of the outcrop is the lamprophyre.  It has intruded the granodiorite (white rock at the top of the photo) and in the middle there is a brown reaction zone of altered feldspars and oxidized (“rusted”) pyrite.  Look closely and you can see some pale flecks in the black rock – these are xenoliths, which are pieces of wall rock that were torn off and incorporated into the magma as it intruded.  On the necklace, I strung a white granodiorite above a black lamprophyre on the left side of the strand.  Below is a closeup of some lamprophyre beads:

Lamprophyre Bead

Here’s a few rough pebbles.  All the rocks below were used in the necklace.  From left to right they are black lamprophyre, brown/green altered rhyolite, red rhyolite pyroclastic, and green epidosite (epidote/quartz rock).

Bead Rocks

Beads in various stages of completion:  All are Santa Rita rocks except the Peruvian pink opal, which is for a different project.

Unfinished Stone Beads

 

Windows in Rocks

We recently acquired a surplus Zeiss Standard petrographic microscope for looking at thin sections of rocks.  It has three high-power objectives, with space for two more objectives on the turret.  For lower power viewing, I still have my Olympus Elgeet POS, which I featured in my 2001 CD-ROM, Collecting and Using Mineral Pigments.  Both microscopes were made about 1980.  The Olympus is wonderful but was considered a student microscope because of its simple, old-fashioned design.  The Zeiss has a wider, brighter field of view, a more versatile design, and higher quality objectives.  It was intended for advanced students, industrial use, and research (though fancier research models were also available).

Several features make a petrographic microscope different from a biological microscope.  The most obvious are the round stage that can be rotated, and the two polarizing lenses (one above the stage and one below it).  This microscope is most commonly used for studying thin sections – transparent slices of rocks – that are are glued to glass slides.

Zeiss Standard and Olympus Elgeet POS Petrographic Microscopes

We got a camera attachment so we can take pictures through both microscopes, and I’ve set up part of my shop to make thin sections, which is just basic lapidary work.  I learned how to make them in 1987 as an undergraduate geology student (coincidentally, the same semester that I learned how to make cabochons).  It takes time and patience, since my method is quite primitive (more on that in another post).  Meanwhile, we’re playing with a few slides that were duplicates from my 1992 Master’s thesis.

So what are we looking at?

Photos below are of a high-grade metamorphosed gabbroic anorthosite from the southeastern Adirondacks, NY.  Anorthosite is a rock made mainly of plagioclase feldspar with a few minor dark iron-rich minerals.  Gem quality iridescent labradorite (“spectrolite”) is from anorthosite from Scandinavia and Madagascar, and slabs of dark anorthositic rocks are among several rock types that are sold as “black granite” for counter tops.  Anorthositic rocks are also found on the moon.

I photographed a tiny piece of the thin section on high power using the Zeiss scope.  The first picture is in ordinary light.  The black grain is two intergrown opaque metallic minerals: magnetite (iron oxide) and ilmenite (titanium oxide).  The Fe-Ti oxide has a rim of pale brown titanite.  On the left is plagioclase feldspar which has been mostly altered to sericite, a cloudly-looking mixture of clay and fine-grained mica.  The green grain in the upper left corner is hornblende.  On the right half is a cluster of mica crystals.  Their striped or woody-looking pattern is unusual, and means that there are probably two types of mica present, most likely biotite and phlogopite.

Titanite Rim on Fe-Ti Oxide

When viewed under polarized light (“crossed polars”), the mica shows beautiful interference colors, the plagioclase looks gray (and it’s easier to see the straw-colored sericite clusters), and the titanite looks relatively unchanged.

Ti Rim on Fe-Ti Oxide, XP

Here’s a nonpolarized lower power view taken through the Olympus scope.  It looks darker than the first photo because the light isn’t as strong, and dark minerals occupy more of the field of view than in the higher power photo.

Ti Rim on Fe-Ti Oxide with Mica

Petrography – the study of rocks in thin section – is essential to a geologist’s training.  Mineral identification is an important aspect, but it also includes recognition of textures, crystallization sequences, alteration and weathering products, and other visual clues to a rock’s compostion and history.  The specialized microscope, the array of odd and challenging optical techniques, and the unique vocabulary make petrography one of the most arcane aspects of geoscience.  For the student, it has a rarified, initiatory quality that is lacking in the more “real world” geological studies such as mapping or identifying fossils.  It is quite demanding, and expertise comes only with experience after studying slides of many different rocks.  Some students struggle with it and are happy to leave it behind as soon as possible.  But for geologists with an eye for color and pattern and a sensitivity to detail, it becomes a valuable skill and a treasured art form.  Many thin sections are extremely beautiful, and each is a window into a rock, revealing secrets that cannot be known any other way.

Old petrography handbooks were illustrated with black and white ink drawings.  Atlases with slick color photos were first published in the mid-1980s.  Since about 2000, modern computers and digital photography have made it easy to create and share excellent petrographic images.  As a student, I was fascinated with the old drawings, and taught myself this rare form of scientific illustration which was rapidly becoming obsolete.  Ink is traditional, but some high-contrast thin sections work fine as pencil drawings.  Here’s a pencil rendering of the slide pictured above, drawn on a 3.5 inch circle that shows the entire field of view on high power.  Compared to the photo, it shows additional Fe-Ti oxide and titanite grains, more mica crystals, and a small cluster of hornblende crystals.  Although this type of drawing cannot show color, it is valuable for illustrating relief, which is the extent to which a mineral appears to stand above the others, or stand out in 3D.  Relief is an important mineral identification property.  This particular slide is a simple example, with minerals that differ strongly in relief, shape, and color.  Beginning with the mineral with highest relief, the sequence here is Fe-Ti oxide – titanite – hornblende – mica – plagioclase – sericite.

Pencil Drawing of a Thin Section

Stone Beads: Santa Rita Green and Purple

This Moon I have been carving stone beads from pebbles that I collected in Sycamore Canyon and other canyons in the Santa Rita Mountains.  Eventually I want to make enough for a necklace.   I have a fairly efficient system for cutting the blanks, drilling holes, carving, hand-sanding, and polishing.  Even so, it’s a slow process, averaging one finished bead a day.  It’s fun to watch the strand grow.  It’s acquired a “Green and Purple” color theme, partly inspired by the rocks themselves and partly by the endemic Santa Rita prickly pear cactus (Opuntia santa-rita), which is pale grayish-green in the summer and turns a distinctive mauve color in winter.  Three of the new beads are shown below.  All are slightly softer than agate and take a soft polish rather than a mirror shine, even when diamond powder is used.  At left is a bead made of diopside (a green pyroxene) and calcite, sometimes called “calcsilicate rock”.  It is from a skarn, a special type of contact metamorphic rock that is produced when granitic magma intrudes limestone or marble.  In the center is a volcanic rock that has been extensively altered to clays and hematite, so its original composition is unknown (it’s from the outcrop pictured below).  At right is an altered and slightly metamorphosed rhyolite; the pistachio-colored mineral is epidote and the dark green veins are diopside.  Rhyolite is a light colored volcanic rock which is equivalent to granite in composition; it is the main rock type of the Santa Ritas but comes in a wide variety of colors and textures.

Three Handmade Stone Beads

Here’s an outcrop of altered and weathered purple volcanic rock with a vein of epidote (yellowish-green), chlorite, and diopside (bluish-green) exposed on a weathered surface.

Green and Purple Outcrop

Here’s the Santa Rita prickly pear in midwinter, growing wild in Chino Canyon.  The green prickly pear in the center of the photo is a more common species, Opuntia engelmanii.

Santa Rita Prickly Pear in Winter

Copper Flutes and Hand Dyed Hemp

These two copper flutes were based on D (small) and Bb (large) 6-hole English tin whistles that I bought years ago.  I played the whistles quite a bit when I was in high school, but quit in college when my asthma became too severe.  The new copper flutes have a larger bore than the tin whistles and a shorter mouthpiece, so the higher notes are easier to blow, and all the notes are quieter and sweeter than a tin whistle.  After some experimenting with hole positions on the old instruments, I added two holes, one at the top and one at the back, so these flutes are fingered like a recorder and are a bit more versatile than a tin whistle.  Unlike the rimblown flute that I posted here a year ago, these are “fipple flutes” and are easier to play (though making them was a lot more work!).  The blocks are carved from manzanita that I collected in the Santa Rita Mountains a couple of years ago.

Flute Mouthpieces

The beads on the larger flute are handcarved from local pebbles.  The bluish-green copper ore is from a local abandoned mine dump, the two striped black dolomite beads are from the Empire Mountains, and the pink and grey rhyolite is from the Santa Rita Mountains.

Today I prepared some fabric for an embroidered wall hanging.  This is a sturdy hemp/cotton plainweave left over from a dress that I made several years ago.  At the top of the photo is the natural undyed fabric which is a warm white.  Below that is the same fabric dyed straw yellow with pomegranate hulls (they are rich in tannin, which provides the color; the dried hulls were crushed and the fabric immersed with them in cold water for several days).  I dyed this fabric a few years ago and have used it for a few jewelry bags etc.  At the bottom is some of the pomegranate-dyed fabric that has been “overdyed” with local clay from my yard (once used for making adobe bricks) mixed with powdered red ochre (hematite).  Of course the clay/iron oxide coating isn’t really “dye” since it doesn’t penetrate the fibers – it just sits on top of them.  But the hemp traps it pretty well and the color is quite even and does not rub off.  The fabric was scrubbed in the wet clay/ochre mixture, left to dry while still covered in it, then washed and dried again.  This process was repeated three times.  I was only working with a quarter yard, so it didn’t take long, and now I have a nice piece of warm, earthy-looking adobe-colored fabric for my project.

Smithsonite Necklace

I finally finished a necklace to hold the smithsonite beads that I carved back in August.  My Pink Bead Necklace is so comfortable that I made this one in a similar style.  Forged from high-carbon steel and black steel wire, with bronze spacer beads cut from a broken Tibetan singing bowl.  The copper beads were cut from scrap tubing, then hammered flat and polished.  The bead at the back was carved from a piece of ore that I picked up at an abandoned copper mine.

I usually like to put reverse twists on this type of forgework.  But that doesn’t work with this thin high-carbon steel stock, since it can’t be quenched in water or it will shatter.  So I just tapered, rounded, and curled the ends.  Although it’s not apparent from the photo, the iron pieces have a “vertical” curve as well as a horizontal one, so the necklace doesn’t lay flat on the ground but it drapes nicely when worn.  The bronze and copper beads will eventually tarnish and will be subtle accents for the “screaming” turquoise color of the beads.

I have one small piece of smithsonite left.  It will probably become an earring.  Sometime this winter I’m hoping to go back to the mine where I collected it.  I’d like to find more of this unusual material, since it makes such beautiful beads.

Smithsonite and Forged Iron Necklace

Earrings for the Autumn Equinox

These Cat Eye and Claw earrings seem appropriate for the Autumn Equinox, with their balance of brown and blue, transparency and opacity, receding earth and rising water.  I carved the “claws” some time ago and only recently made the “cat eye” cabochons to go with them.  Settings are sterling silver with fine silver bezels and frosted aquamarine beads, 2.5 inches long, not including the earwires.

LEFT:  Rose gold bead (made in my shop from recycled metals), Oregon picture jasper cabochon, Guatemalan “Olmec Blue” jade carving (jadeite; carved the same on both sides).

RIGHT:  Bronze bead (cut from a broken Tibetan singing bowl), Namibian blue tigereye cabochon (the metallic line down the center is hematite), Siberian fossil mammoth ivory (the rare blue color is from vivianite, an iron phosphate mineral).

Cat Eye and Claw Earrings

We’re Back

OK, we’re back, and the computer has a new graphics card.  Meanwhile I’ve been working in the shop, drawing, staring at a ”to-finish” list of too many projects, and setting priorities.  I re-did the Pink Necklace to include some forgework and more stone beads, which frees up the iron beads to use for something else.  It’s also more comfortable (and flashy!) to wear.  Hot-forged sterling silver and high-carbon steel, with the beads strung on black steel wire.  I carved two dark purple beads from fine-grained volcanic pebbles that I collected several years ago and have been using to decorate my yard.  The rock is extensively altered (mostly to hematite and clays) so it’s not as hard as the original minerals would have been, and takes a soft polish rather than a high shine.  The bright pink bead at the back of the necklace is Peruvian opal.  I carved this from some high-grade rough that a friend gave me several years ago.  This material is mostly an opaque pink chalcedony that forms in thin layers with swirling stringers of translucent pink, white, or colorless opal.  The color is a bit too bright for the front of the necklace (where I want the pink chalcedony to be the focus) but it is a nice accent for the back.

Pink Necklace II

Now it needs some matching earrings.  I am working on a forged silver/iron set with small pink opal beads, but they will take some time.  Meanwhile, these simple wire ones will do:

Pink Earrings

I also made a forged pair of Moonlight Curly Cones, inspired by the Ironwing Tarot Ten of Bells card.  These are hot-forged sterling silver and high-carbon steel, like the necklace.  They are for sale on my website, since they ought to match anything black and white!  I have enough silver wire left for a couple more pairs of earwires (probably for me), but with silver at $44 an ounce, I won’t be buying any more for awhile.  I’m almost out of black steel wire, and once I’ve finished the necklace that is sitting nearly completed on my desk, I have chosen not to get any more, in order to focus on expanding my forgework.

Moonlight Curly Cones

The new computer has spawned a host of compatibility issues that mean that some things that used to be easy are now either impossible or too time-consuming to be worth the trouble.  So I am spending more time at the drawing table and less on the computer, and am not tackling any printing/publishing/drawing reproduction projects for awhile.

Handcarved Smithsonite Beads

Today I measure wealth and abundance in the ancient way, with a handful of skystones…although these aren’t turquoise.  I cut this set of smithsonite beads from a single chunk of pale bluish-white, chalky-looking rock that I picked up at an old copper mine.  The black material is mostly manganese oxide but there are also a few tiny crystals of murdochite, a rare lead-copper halide.  The center bead is 15 mm in diameter.  Smithsonite (ZnCO3) is an ore of zinc and is usually found as translucent, pearly-looking bubbly layers in a variety of pastel colors.  Massive smithsonite has a sugary texture, like marble, but is heavier and a bit harder.  The beads might be confused with a copper ore, but they are more translucent than turquoise and softer than chrysocolla.  The polish on these is rather uneven because some parts of the rock were soft and chalky and others were hard and glassy; this is one reason (other than rarity) why smithsonite isn’t often cut as a gem.  When it is cut, it’s usually as cabochons, not beads.  Still, they turned out much prettier than I expected.  The polishing brought out a lot of color and patterns, and the beads have a lot of presence.  The hardness is only 4 (same as fluorite), so they would be too easily scratched for a bracelet.  They will make a nice necklace but I’ll have to make some more beads – probably from various copper ores – to go with them.

Handcarved Smithsonite Beads

Pink and Iron Necklace

I’ve had these beads for awhile, intending them for several different projects, but they work very well together.  I’ve always liked the pink/black color combination, especially when one of them is metallic.  Today the idea of a simple necklace of earthy, comforting, and familiar materials was very appealing.  It made an easy, peaceful project for the waning moon.  This Pink Earth choker is made from antique African forged iron heishi beads, Mexican terracotta beads with a shiny pale pink glaze, two pieces of sterling silver tubing that I cut, filed, and polished, and a pink agate bead that I carved last year from a pebble that I found in the Empire Mountains.  The purplish-pink color in the agate comes from tiny flecks of dark red hematite scattered through translucent chalcedony.  This is the same type of inclusion that forms “strawberry quartz” but it is rare in agate (hematite in agate is usually finer grained and brighter red).  The clasp is 14-gauge sterling silver wire.

Pink Earth Necklace

 

Mined and Refined: Amethyst Rings

Amethyst Ring Set

Mined and Refined:  Amethyst is a set of two rings that can be worn together or separately.  The larger one is made from a piece of iron pipe that was hot-forged to the proper size, then drilled, carved, and polished.  The silver bezel cup is riveted to the iron ring.  It is set with a very pale natural amethyst crystal from a small ”Keokuk-type” geode that I collected on the North Rolling Fork River in central Kentucky many years ago.  I’ve seen hundreds of these geodes but only one with amethyst crystals and a couple with smoky quartz.  Most sedimentary geodes of this type have colorless or white quartz crystals.

The companion ring is hammered sterling silver 14-gauge wire, set with a 6mm faceted light purple smoky amethyst.  The point on the underside of the stone had a small but noticeable chip (this is a common flaw in round faceted stones, and is why “brilliant cut” diamonds have a culet, which is a tiny facet that blunts the point).  I polished a tiny dome on the point.  It removed the chip and gives the stone a visual “hole” in the center, like the pupil in an eye, which looks unusual and adds a bit of interest.  Although this is considered a low quality stone (high-grade amethysts are darker and more intense purple), I thought its subtle moody color made it a perfect match for the pale, slightly milky crystal in the iron ring.

These are small rings (size 5) that I made to fit my pinkie.  Both stones have sentimental value for me but are not worth much by traditional gem-grading standards.   One reason that I don’t make more rings is that I do not feel (at least in my own work) that the end result justifies the amount of time involved.  The iron ring in particular was a lot more work than it looks.  But it was an interesting project and should be fun to wear.

Iron Ring with Amethyst Crystal in Silver