Blog
-
Porosity, and what stone takes in
Why one stone accepts dye and another refuses it comes down to connected pore space — the property behind most treatments and most staining.
-
Density, and what a stone weighs
Specific gravity separates jadeite from serpentine cleanly and separates nothing in the crowded middle. The method, the arithmetic, and the error bars.
-
Type A, B and C jadeite
The letters are a treatment classification, not a quality grade. What each one means, what it applies to, and why a listing's Grade A is neither.
-
Chalcedony, agate, and jasper
The fine-grained quartzes are quartz by composition and a different material in the hand: tougher, waxier, and the easiest of all stone to dye.
-
Marble, calcite, and the soft white stones
A white or honey-banded tool is very often a carbonate: soft, cleavable, and the one material a household acid identifies outright.
-
Testing a stone at home
The scratch test, the water test, the loupe and the kitchen scale — what each one actually establishes, and the much longer list of what none of them can.
-
What bian stone is
Bian stone is a category name, not a mineral species. Understanding what it does and doesn't specify explains why the label tells you so little.
-
Hardness, toughness, and why tools break
Hardness resists scratching. Toughness resists fracturing. They're different properties, and the harder stone is often the one that snaps.
-
How imitation stone is made
Dyeing, waxing, polymer impregnation, reconstitution, glass and resin — each is a different process, and each leaves a different trace behind.
-
Nephrite, jadeite, and what jade means
Jade is two unrelated minerals with different compositions and hardnesses — plus a long list of trade names for things that are neither.
-
What a gemmologist actually does
The instruments that identify a stone, what each one measures, and why an opaque polished tool is a harder case than a faceted gem.
-
What a certificate of authenticity proves
A laboratory report and a certificate of authenticity are different documents. One states test results; the other states that the seller says so.
-
Horn, bone, and wood as tool materials
Organic tool materials behave nothing like stone: they take up moisture, move with it, and soften with heat rather than cracking.
-
Stainless steel and metal tools
Steel does not fail like stone. It bends instead of shattering, and the interesting question is whether a metal tool is solid steel or a plated casting.
-
Why stone feels cold
A stone at room temperature is not cold. It feels cold because it conducts heat out of your skin faster than your skin can replace it.
-
How a stone tool is cut and polished
Every stone tool passes through sawing, shaping, a sequence of finer abrasives and a polish. What the workshop skipped is usually visible on the object.
-
Reading a polished surface
A polished face records the material's structure and the workshop that finished it. Undercutting, pitting and orange peel each mean something specific.
-
Veins, inclusions, and internal lines
The lines inside a stone are its history. Some are healed structures the material grew around; others are open cracks waiting to finish the job.
-
Heat, irradiation, and coatings
Dyeing is the treatment everyone knows about. Heating, irradiation and surface coating are equally common, and each leaves a different kind of trace.
-
Amethyst, citrine, and heat treatment
Amethyst's purple is a lattice defect, not a pigment — which is why heat converts it to yellow, and why most commercial citrine started out purple.
-
Amazonite and the feldspars
Amazonite is a green potassium feldspar, and feldspars have cleavage — planes of weakness that no amount of hardness compensates for.
-
Aventurine, goldstone, and the glitter
Aventurine glitters because of flat mineral flakes inside it. Goldstone glitters because someone put copper in molten glass. They are not the same.
-
Obsidian, and natural glass
Obsidian is volcanic glass — genuinely amorphous, genuinely a stone. Which makes it the one material where looking like glass proves nothing.
-
Rose quartz, and what makes it pink
Rose quartz is a cloudy pink quartz aggregate coloured by microscopic inclusions — which is why the clear, evenly pink version is usually something else.
-
Serpentine, the stone most green tools are
Serpentine is a mineral group, not a species, and it is what a large share of inexpensive green stone tools are made from. Here is how it behaves.
-
Synthetic, imitation, simulant, composite
Four words that get used interchangeably and mean four different things. A synthetic stone is the real mineral; an imitation contains none of it.
-
How stone trade names work
Trade names in the stone market follow a small number of grammatical patterns. Learning the patterns is faster than memorising the individual names.
-
Lustre, translucency, and what light shows
Lustre is how a surface reflects; translucency is how the body transmits. Both are observable without equipment, and both are routinely misread.
-
Where colour in stone comes from
Colour in a mineral comes from trace metals, lattice defects, inclusions or structure — which is why colour is the least reliable way to identify a stone.
-
Crystalline, microcrystalline, and amorphous
Whether a stone is one crystal, a mass of tiny interlocking ones, or no crystal at all explains how it breaks, how it shines, and how light passes through.