This was an interesting article but unfortunately extremely limited. I would’ve hoped for a much more in depth discussion from such a learned author as Mr Clarke.
From my experience both as judge and competitor, judging in lapidary competitions is somewhat vague and ill-informed when it comes to carving. Unfortunately most judges have little if any in depth carving experience. Most have backgrounds in cabochon, faceting and jewellery making where the criteria for judging these items is relatively clear.
A perfect, high gloss polish (amongst other matters) is essential for cabochons and faceted stones to achieve high scores, and it does take a trained eye to distinguish the polish.
However, polish is one of a number of areas where there is a misunderstanding of its application to carving gemstones. Gem stone carvings are the fine arts of the lapidary crafts and the concept of polish is far more nuanced. Polish is akin to tone in fine art and is used to enhance the subject in specific ways. Comments such as “…any polished areas should still be as glassy as any other gem” are unhelpful in understanding and evaluating gemstone carving.
One only need to carefully study the photos in the article to realize each carving has a distinct level of polish and some with multiple levels of polish. Sometimes the material will determine the polish, sometimes the detail will determine the polish and sometimes the artistic goal will determine the polish. The master carver will use the appropriate levels of polish to achieve his, or her, goals in each case.
To have a good appreciation for the value of cabochon and faceted gems one should be familiar with the criteria for assessment of those items in lapidary competition. And for gemstone carvings one should also research and be familiar with artistic periods and styles and the provenance of authorship and ownership.