SILICON
Specimen sii-4

Dims: 5.5 x 4.69 x 2.5" (13.9 x 11.8 x 6.3 cm)

Wt: 1 lb, 5.3 oz. (603 g)

(laboratory-grown)

This intriguing piece consists of a large, amorphous chunk of raw Silicon that was originally grown in a laboratory. It appears to be made up of many smaller pieces that have been fused together. The Silicon has the silvery-gray color, metallic luster and low density that are standard for such material. One face appears to have undergone some oxidation during the fusion process, as it is coated with a thin, cracked layer of clear glass.

Dims: 4.56x2.79x2.33" (11.59x7.09x5.91cm)

Wt: 25.82oz (732g)

(lab grown, probably USA)

Actually, this chunck of pure silicon does not look like the usual single-crystal boules used to manufacture computer chips, but rather like a bi-product of that process (forming on the walls or floor of the over, or crystallizing when the melt is allowed to cool). One side of the specimen is nearly perfectly flat, except for a detailed pattern of ridges that look like crystals forming on the surface of a melt that has cooled. On the opposite side is an area that looks like a cavity within which some distinct crystals have formed, although I do not see how this could have happened in the lab, unless this is an artifact of the production of pure silicon from a slag containing other components that maintained a molten space within which the crystals could form.

Dims: 4.51x3.11x3.04" (11.46x7.91x7.73cm)

Wt: 15.77oz (447g)

(lab grown, probably USA)

This is a most unusual specimen of silicon. Generally, we see common boules used to make computer chips, or sometimes re-melts of ship components, but this is different. The outside is rough, a texture imposed by the container in which it formed, except for the narrow bottom (in the image) which is quite smooth but with some texture (almost like it was spray-painted). The inside (see the top view) has the typical feel and luster of silicon boules, with a concentric and somewhat hollowed-out growth pattern that defies my understanding of how it could have formed. There is a moderate amount of damage, almost entirely to the thin, fragile edges of the rim. I do like this oddity.

Dims: 5.06x5.04x5.02" (12.86x12.80x12.76cm)

Wt: 41.45oz (1175g)

lab grown, USA

This is the tip of a silicon boule, used to make computer chips. It is perfectly round and the cone shape varies in width in a sinusoidal pattern. The surface of the silicon has striations, caused by uneven pulling rates from the molten silicon bath from which it was grown. It appears to have been pulled exactly a millimeter at a time, and the length of time at each stage determines the width of the resulting boule. It was cut flat at the base but not polished, and there is some damage, probably caused by the discarding of the now usless tip of the boule - the really valuable part is the long uniform width part that they slice into wafers for computer chips.

Dims: 3.96x3.85x2.77" (10.06x9.79x7.04cm)

Wt: 27.13oz (769g)

lab grown, USA

This is the tip of a silicon boule. The rest of the crystal may have been used for memory or computer chips. While showing no crystal form, boules like this are grown as large single crystals so that crystal defects are at a minimum. Numerous fracture areas near the edges reveal a conchoidal fracture pattern and a very bright luster. The sides of the specimen show an interesting stepped growth pattern, showing the steps as the boule was pulled from the melt.

dims mm=97.32x66.70x65.58

wt g=80

lab grown, USA

This neat little specimen of pure silicon has the shape of a top, although I don't recommend spinning it. The "handle" end shows the typical striations caused by the stepwise pulling from the melt, and the bottom is a nearly perfectly smooth reflecting convex surface.

dims mm=108.54x66.86x57.99

wt g=599

lab grown, USA

I'm not sure how this specimen acquired its shape. My best guess is that molten silicon was poured into a container with a textured side wall, then gradually cooled and cracked near the center. Individual crystals are visible, as fine acicular growths generally in a radial pattern, plus the center has radial "collumns" likely caused by cracks upon cooling.