LOL! Wtf is "shark skin" ?
In fact, today's best and most costly sharkskin fabrics ...... contain some percentage of synthetic fibers, and can thereby feature a heightened metallic-like sheen, with added flexibility (often owing to a mere 2% Lycra blend), which had been seldom otherwise achievable, even in the ranks of the elite "Golden Fleece", "Royal" (or an array of other designation of the most costly "natural sharkskin's" revered status) fabrications of yester-year ... owing no other than to ... newly engineered synthetic fiber blends.
Recently, as of 2010, innovative use of tight ring-spun Pima and/or Egyptian cotton fibers added to blends {developed using AUTO-CAD fabric modeling by Italian [Brescia: Italy's millenniums old historical textile center]} by engineers, have resulted in a new breed of ultra-dense, lightweight and resilient "Super-Sharkskin(s)" that boost(s) all the best attribute(s), and then some, of former generations' of the fabric's variants -- many at half the cost(s), while still using percentages of mohair, silk, wool and/or other "natural, synthesized and/or synthetic fiber/s blend(s)" {multiple percentage combinations exist in the market}.
Moreover, today, use of ultra-high thread counts -- not formerly attainable -- that achieve e.g., over 300 to 1000 threads "per square inch" thereby impart heightened "shimmer and sheen", having been formerly somewhat attained (with less luster and sheen) by the addition of artificial e.g., nylon, acetate, orlon, polyester (this latter fiber appearing in the 1980's variants), as has been long used in most lower cost "artificial sharkskin" fabrics of the 50's, 60's ... and later in the '80's [think "Rock-a-Billy] that dominated the market; many, using small percentage ratios of such fibers, with the largest percentage of fibers used, these days, being conventional wool and/or the coveted Marino wool fibers spun to new/enhanced/innovated specifications.