Tincalconite
An
experiment:
When Borax Na2(B4O5)(OH)4·8H2O
is dehydrated, the new mineral Tincalconite Na2(B4O7)·5H2O
forms, so Tincalconite pseudomorphs of Borax are not surprising, given
the dry environment in which both are found. What is a surprise,
though it really shouldn't be, is that these specimens can become quite
hot when placed in water! Thus we have
Borax + heat - water = Tincalconite
where the heat is supplied by the environment and serves to evaporate (and thus chemically remove) the water. So naturally,
Tincalconite + water = Borax + heat
I experimented with a few pieces (experimental pieces are available for $3), and retrieving a piece after 10 seconds in a bowl of water and holding it in your hand results in a very noticeable amount of heat release. The pieces retain their shape but I think the edges become a bit more rounded, so DON'T do this with your favorite display piece.
You
can only reliably do that experiment once, so gather everyone around
before you start! I was able to "re-set" some of them
by placing them in a 250-degree oven for 3 hours - this was really too
hot, though, because 1/2 of my pieces crumbled. So I would suggest
a lower temperature (maybe 200-degrees?) for a longer time (maybe overnight?)
If your pieces crumble when you try to reset them, you can still do
an experiment by putting the crumbles into water and showing your audience
that the water gets warmer.
History:
These
specimens were collected in 1979 by John Seibel and the late Jim Minette
from an underground locality. Now that locality is part of the
Boron open pit, and the Tincalconite site is gone.
click on images for larger
views
click
on images for larger views
TpB11-02
Tincalconite ps Borax $75
collected by John Seibel and Jim Minette
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
16.0 cm x 8.0 cm x 7.5 cm
This is a large complex piece whose shape resembles a Feldspar.
click on images for larger views
click on images for larger
views
click on images for larger views
TpB11-03
Tincalconite ps Borax $80
SOLD
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
17.6 cm x 14.0 cm x 10.0 cm
This is quite a large and wonderfully complex piece displaying both fine structure and big, sharp, blocky crystals. The yellow visible in the lower right photo seems to be a remnant of the original Borax.
click on images for larger
views
TpB11-04
Tincalconite ps Borax $65
SOLD
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
11.8 cm x 8.5 cm x 8.5 cm
A nice large piece with some sharp, complex crystals visible in the upper right photo. The yellow visible in the lower photo seems to be a remnant of the original Borax.
click on images for larger views
TpB11-05
Tincalconite ps Borax $60 SOLD
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
11 cm x 10 cm x 4.3 cm
The contrast between the two sides is particularly striking on this one.
click on images for larger views
TpB11-06
Tincalconite ps Borax $32
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
13.7 cm x 6.5 cm x 3.8 cm
This is a fairly large piece, but it does not display as much of the crystal faces as the other large pieces, hence the lower price. It does, however, have a nice patch of fine structure visible in the left photo (especially visible in the larger image) that is slightly yellow due to remnants of the Borax.
click on images for larger
views
TpB11-07
Tincalconite ps Borax $55
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
12 cm x 7.5 cm x 6.5 cm
A big piece with some very nice large faces at one end and some finer, more complex crystal shapes at the top, better than the photos.
click on images for larger
views
TpB11-08
Tincalconite ps Borax $50
SOLD
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
10.5 cm x 9 cm x 8.5 cm
Another nice large, chunky specimen with some good sharp faces.
click on images for larger views
TpB11-09
Tincalconite ps Borax $16
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
6 cm x 5.5 cm x 3 cm
A medium-sized piece with a few interesting features front & back.
click on images for larger views
TpB11-10
Tincalconite ps Borax $22
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
7 cm x 4.5 cm x 3.8 cm
Another medium-sized piece with some interesting features & some good striations.
click on images for larger views
TpB11-11
Tincalconite ps Borax $40 SOLD
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
6.5 cm x 5.5 cm x 5 cm
This is my favorite of the medium-sized pieces. It has sharp crystal shapes, nice blocky and fine structure, and distinct striations.
click on images for larger views
TpB11-12
Tincalconite ps Borax $18
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
6.3 cm x 4.5 cm x 3.8 cm
Some nice faces and striations on this medium-sized piece.
click on images for larger views
TpB11-14
Tincalconite ps Borax $20
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
4.1 cm x 3.5 cm x 2.4 cm
A nice blocky little crystal with some good striations on the sides.
click on images for larger views
TpB11-15
Tincalconite ps Borax $18
SOLD
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
4.1 cm x 3.5 cm x 2.0 cm
Another blocky little crystal with some good striations and an interesting overall shape.
click on images for larger views
TpB11-16
Tincalconite ps Borax $17
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
4.2 cm x 1.8 cm x 1.5 cm
Good sharp little crystal.
click on images for larger views
TpB11-17
Tincalconite ps Borax $18
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
3.8 cm x 2.5 cm x 2.1 cm
This interesting specimen is less white than the others, and the spots & patches of pink are real. I don't know for sure what causes the pink, but I'm guessing it is algae. Halite from the Searles Lake area is known to turn pink from algal inclusions, and the salt flats that we drive by on 395 in eastern California periodically turn pink.
click on images for larger views
TpB11-18
Tincalconite ps Borax $12
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
4.5 cm x 3.0 cm x 2.6 cm
A smallish piece with good striations.
click on images for larger views
TpB11-19
Tincalconite ps Borax $21
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
7.4 cm x 4.3 cm x 3.5 cm
A decent medium-size piece with interesting faces and striations.
click on images for larger views
TpB11-20
Tincalconite ps Borax $21 SOLD
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
8.5 cm x 4.0 cm x 3.0 cm
A weirdly-shaped piece with plenty of faces and striations.
click on images for larger views
TpB11-21
Tincalconite ps Borax $22
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
5.0 cm x 5.0 cm x 2.5 cm
Partial crystal shapes, sharp faces and nice striations.
click on images for larger views
TpB11-22
Tincalconite ps Borax $18 SOLD
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
4.7 cm x 4.3 cm x 2.5 cm
Good crystal shapes - large and small - and sharp faces.
click on images for larger views
TpB11-33
Tincalconite ps Borax $16 SOLD
Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron,
Kramer District, Kern Co., California
5.2 cm x 4.2 cm x 2.4 cm
Some nice sharp crystal shapes.
Here are some more Tincalconite ps Borax from the Baker mine/U.S. Borax Mine, Kramer Borate deposit, Boron, Kramer District, Kern Co., California:
TpB11-30 Tincalconite ps Borax (3.1x2.1x2cm) $12
- click on images for larger views
TpB11-31 Tincalconite ps Borax
(4.5x3.5x2cm) $10-
click on images for larger views
TpB11-32 Tincalconite ps Borax (3.9x3.5x2cm) $15
- click on images for larger views
TpB11-34 Tincalconite ps Borax (3.3x2.3x2cm) $12
- click on images for larger views
TpB11-35 Tincalconite ps Borax (4.3x2.5x2cm) $12
- click on images for larger views
TpB11-36 Tincalconite ps Borax (5x2x1.2cm) $10
- click on images for larger views
There are also some pieces suitable for experiments @ $3 each.
or select a gallery from the table below:
Questions? Please send me an email.
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